The airport terminal was hit, a drone exploded near a school, injuring civilians, and another drone was shot down, as the war in the Middle East spilled over Iran’s northern border.

Azerbaijan’s President Ilham Aliyev condemned the “act of terror”, demanding an explanation and apology from Tehran.

On Friday he went further, announcing the withdrawal of staff from Azerbaijan’s embassy in Tehran and consulate in Tabriz “for their own safety”, and state media said the military had been placed on maximum combat readiness.

Aliyev also touched on Iran’s ethnic Azerbaijani population on Thursday – a sensitive subject for Tehran.

Iran denies any role in Thursday’s strikes and has suggested the attack may have been an Israeli false‑flag operation.

Azerbaijan, a small but strategically important Caspian country bordering Russia, Iran, Armenia and Georgia, is now being pulled closer to the heart of a much bigger confrontation.

Nakhchivan is an isolated Azerbaijani territory bordering Iran, Turkey and Armenia, making it particularly exposed during times of conflict.

The drones triggered Aliyev’s strongest public attack on Tehran since he took office.

He said the Iranian forces behind the strike were “ugly, cowardly and disgusting” – an unusually blunt personal insult for a head of state.

But his anger went beyond words, saying that “independent Azerbaijan is a place of hope for Azerbaijanis living in Iran”.

Baku has long avoided this line because of how sensitive it is for Tehran.

Iran is home to an estimated 20-25 million ethnic Azeris, who make up its largest minority group and are concentrated in the north-west along the Azerbaijan border.

The Islamic Republic has consistently regarded their identity and political affiliations as issues of utmost sensitivity. Tehran views any notion of Azerbaijani identity extending beyond its borders as a potential challenge to internal unity.

Aliyev has rarely spoken about Iranian Azeris in such explicitly aspirational terms and doing so now appears to be a calculated move.

Iran is under intense pressure not just from the war but from internal unrest and political uncertainty and Aliyev’s message comes across as a warning to Tehran: any attempt to pressure Azerbaijan militarily or diplomatically could result in a response from Baku, including one that affects Iran’s internal stability.

Iranian Azerbaijanis have long complained that they are denied basic cultural rights, including education in their own language.

Several Azerbaijani activists, journalists and language campaigners are currently imprisoned in Iran, facing charges ranging from “propaganda against the regime” to “conspiracy against national security”.

They are also a politically significant community. This week the exiled crown prince, Reza Pahlavi, has been urging Iranian Azerbaijanis, among other ethnic minorities, to rise up against the regime.

Iran’s current President, Masoud Pezeshkian, is himself an ethnic Azerbaijani and the late Ayatollah Ali Khamenei – who was killed in the opening salvo of US-Israeli strikes on Saturday – was also claimed to have Azerbaijani roots.

Some of Iran’s shahs across the centuries were ethnic Azerbaijanis as well.

One of its most influential rulers, Shah Ismail Khatai, even used Azerbaijani as the first language of his palace in the 16th Century – a reminder of how deeply Azerbaijani culture once shaped the Iranian state.

But none of these facts have helped Azerbaijanis in Iran to have lessons taught in their own language.

Despite their shared Shia Muslim identity, Iran and Azerbaijan have grown apart politically, and tensions worsened after Azerbaijan’s military victories in the 2020 and 2023 Karabakh wars, which were helped by Turkish and Israeli-made weapons.

Iran views Baku’s close defence partnership with Israel as a serious threat.

Iranian officials and media have repeatedly accused Azerbaijan of helping Israeli intelligence operate along Iran’s northern frontier – claims Azerbaijan denies.

Azerbaijan’s ties with Israel extend beyond security. Israel relies heavily on Azerbaijani oil, and the two countries maintain close political and intelligence co-operation.

For Tehran, this collaboration is at the centre of its suspicion.

Azerbaijan, for its part, has long resented Iran’s political and military support for neighbouring Armenia, seeing it as direct interference in a conflict central to its own security.

That history of mistrust is an important backdrop to Thursday’s escalation, shaping how Baku interprets every move coming from Tehran.

Iran opposes the establishment of a land connection between Azerbaijan and its Nakhchivan exclave. Tehran has consistently objected to Armenia potentially allowing Azerbaijan a land corridor to the territory.

The plane is thought to have come under fire from Russian air defence systems as it tried to land in Chechnya before being diverted to Kazakhstan, where it crashed.

On Saturday, Russian President Vladimir Putin apologised to the Azerbaijani president over the downing of the plane in Russian airspace – but stopped short of taking responsibility.

Aliyev accused Moscow of an initial “cover up” over its involvement in the crash. While accepting Putin’s apology, he said Russia “must admit its guilt” and pay compensation.

The Azerbaijan Airlines plane had been en route from Baku, the capital of Azerbaijan, to the Chechen capital of Grozny on 25 December when it is thought to have come under fire.

Flight J2-8243 was forced to divert from Chechnya and crashed near Aktau, in Kazakhstan, killing 38 of the 67 onboard.

Most of the passengers on the flight were from Azerbaijan, with others from Russia, Kazakhstan and Kyrgyzstan.

Aviation experts and others believe the plane’s GPS was affected by electronic jamming and it was then damaged by shrapnel from Russian air-defence missile blasts.

But Aliyev said that, in the days following the incident, “Russian agencies put forward versions [of events] about the explosion of some gas cylinder” which “clearly showed that the Russian side wants to cover up the issue”, according to a transcript of an interview with state media.

He also said that some in Russia had latched on to a theory that the plane had been hit by birds. Aliyev described both theories as “foolish and dishonest”.

The Azerbaijani president accepted that the plane had been shot down accidentally, but said that in the first three days following the crash, “we heard only absurd versions from Russia”.

Baku made a series of demands to Moscow on Friday over the incident, he said, only one of which – an apology – had so far been met.

On Saturday, Putin said the “tragic incident” had occurred when Russian air defence systems were repelling Ukrainian drones, and expressed his “deep and sincere condolences to the families of the victims”.

The Russian president acknowledged that the plane had repeatedly tried to land at Grozny airport, in Chechnya.

However, at the time the cities of Grozny, Mozdok and Vladikavkaz were “being attacked by Ukrainian unmanned aerial vehicles, and Russian air defence systems repelled these attacks”, Putin said.

Ukraine’s President Volodymr Zelensky said Russia must “stop spreading disinformation” and that the damage to the aircraft’s fuselage was “very reminiscent of an air defence missile strike”.

The Kremlin read-out made no direct admission that the plane had been struck by Russian missiles.

Aliyev said Baku had demanded Russia “admit its guilt”, punish those at fault, and pay compensation to Azerbaijan and the injured survivors of the crash.

Azerbaijan and Russia are allies. The Azerbaijani president said: “No one would have thought that in a country that is friendly to us, our plane would be fired at from the ground.”

His remarks came as Azerbaijan paid tributes to the pilots and passengers of the downed plane.

Three crew members – Captain Igor Kshnyakin, co-pilot Alezander Kalayaninov and flight attendant Hokuma Aliyeva – were given distinguished honours for landing the plane in a way that allowed 29 people to survive, even though it led to their own deaths.

In his first comments on the Christmas day crash, Putin said the “tragic incident” had occurred when Russian air defence systems were actively repelling Ukrainian drones.

It had been reported the plane came under fire from Russian air defence systems as it tried to land in Chechnya – forcing it to divert across the Caspian Sea.

It crash-landed in Kazakhstan, killing 38 of the 67 on board.

The Kremlin released a statement on Saturday noting Putin had spoken to Azerbaijan’s president Ilham Aliyev by phone.”(President) Vladimir Putin apologised for the tragic incident that occurred in Russian airspace and once again expressed his deep and sincere condolences to the families of the victims and wished a speedy recovery to the injured,” the statement said.

Prior to Saturday, the Kremlin had not yet commented on the crash. But Russian aviation authorities had said the situation in the region was “very complicated” due to Ukrainian drone strikes on Chechnya.

Aviation experts and others in Azerbaijan believe the plane’s GPS systems were affected by electronic jamming and it was then damaged by shrapnel from Russian air defence missile blasts.

Survivors had previously reported hearing loud bangs before the plane crashed, suggesting it had been targeted.

Azerbaijan had not officially accused Russia this week, but the country’s transport minister said the plane was subject to “external interference” and damaged inside and out as it tried to land.

US defence officials on Friday had also said they believed Russia was responsible for the downing.

In Saturday’s phone call, Putin acknowledged that the Azerbaijan Airlines plane had repeatedly tried to land at Grozny airport in Chechnya on 25 December.

At the time, Grozny, Mozdok and Vladikavkaz were being attacked by Ukrainian drones and Russian air defense systems had repelled those attacks, Putin said according to the Kremlin’s statement.

Moscow noted that Russian investigators had launched a criminal investigation. Azerbaijan had already announced it would launch an investigation.

Thirty-eight people died when the Embraer jet came down at high speed, bursting into flames 3km (1.9 miles) short of the runway at Aktau airport.

The plane had originally tried to land at Grozny airport in southern Russia, but witnesses have spoken of an explosion before it was diverted across the Caspian Sea to Kazakhstan.

The head of Russia’s civil aviation agency said on Friday that the situation in the Chechen capital was “very complicated” and that a closed-skies protocol had been put in place.

“Ukrainian combat drones were launching terrorist attacks on civilian infrastructure in the cities of Grozny and Vladikavkaz,” said Dmitry Yadrov, head of Rosaviatsia, in a video statement posted on Russia’s Tass news agency.

“Because of this a ‘Carpet plan’ was introduced in the area of Grozny airport, providing for the immediate departure of all aircraft from the specified area,” he said. “In addition, there was dense fog in the area of Grozny airport.”

Azerbaijan Airlines did not detail the physical and technical interference, and the government in Baku has avoided directly accusing Russia, possibly to avoid antagonising President Vladimir Putin.

However, aviation experts and pro-government media in Azerbaijan believe the plane was damaged by shrapnel from Russian air-defence missile explosion.

“These are missile fragments that damaged the hydraulic system. The plane’s controls operate based on hydraulics,” veteran Azerbaijani pilot veteran pilot Tahir Agaguliev told Azerbaijani media.

Flight attendant Zulfuqar Asadov who was among 29 survivors on the crashed plane told local media that the plane was “hit by some kind of external strike”.

“The impact of it caused panic inside. We tried to calm them down, to get them seated. At that moment, there was another strike, and my arm was injured.

“In a social media post, Azerbaijan Airlines said it was suspending flights to seven Russian cities in response to the crash “for security reasons”.

It had already halted flights to Grozny and Makhachkala in neighbouring Dagestan, but has now added the cities of Sochi, Volgograd, Ufa, Samara and Mineralnye Vody.

Israel’s flagship airline, El Al, has meanwhile suspended all flights to Moscow, citing developments in Russian airspace.

Ukrainian presidential spokesman Andriy Yermak has said Russia must be held responsible for the crash.The Kremlin has refused to comment on reports that the Azerbaijan Airlines plane was hit by Russian air defence.

“An investigation into this aviation incident is underway and until the conclusions are made as a result of the investigation, we do not consider ourselves entitled to give any assessments,” said spokesman Dmitry Peskov.

Vigils have been held in Azerbaijan to honour the pilots, who are credited with saving lives by managing to land part of the plane, despite themselves being killed in the crash.

Kazakh authorities have been treating the injured and working closely with Azerbaijan on the investigation. However, they have refused to give details of their crash investigation.

Reports in Baku suggest both Russia and Kazakhstan proposed having a committee from the Commonwealth of Independent States (CIS) – a regional organisation dominated by Russia – investigate the crash, but Azerbaijan had instead demanded an international inquiry rather than one involving former Soviet countries.