Platform monitor Downdetector says it had more than 1.6 million reports of problems with the social media site from users around the world on Monday.

“We’re not sure exactly what happened but there was a massive cyber-attack to try and bring down the X system with IP [Internet Protocol] addresses originating in the Ukraine area,” Musk said in an interview with the Fox Business channel.

However, Ciaran Martin, professor at Oxford University’s Blavatnik School of Government told the BBC that explanation was “wholly unconvincing” and “pretty much garbage.”

Prof Martin – former head of the UK’s National Cyber Security Centre – says it looks as if X was targeted by what’s known as a distributed denial of service (DDoS) attack, where hackers flood a server with internet traffic to prevent users from connecting to a website.

“It’s not that sophisticated – it’s a very old technique,” Mr Martin told Radio 4’s Today programme.

“I can’t think of a company of the size and standing internationally of X that’s fallen over to a DDoS attack for a very long time,” he added.

He said the incident at X “doesn’t reflect well on their cyber security.”

Many users trying to access the platform and refresh feeds on its app and desktop site during Monday’s outages were met with a loading icon.

Musk, who has been a frequent critic of Ukraine and its President Volodymyr Zelensky, has offered no evidence to support his claim and did not say whether or not he thought state actors were involved.

He posted on X that “either a large, coordinated group and/or a country is involved”.

But Prof Martin said tracing IP addresses “tells you absolutely nothing,” because hackers in this situation would hijack devices from all over the world.

The BBC has approached the Ukrainian embassy in Washington DC for comment.

Alp Toker, director of Netblocks, which monitors the connectivity of web services, said its own metrics suggested the outages could well be linked to a cyber attack.

“What we’ve been seeing is consistent with what we’ve seen in past denial of service attacks, rather than a configuration or coding error in the platform,” he told the BBC.

He said the organisation has seen several major outages spanning more than six hours on Monday, “each having global impact”.

“This is amongst the longest X/Twitter outages we’ve tracked in terms of duration, and the pattern is consistent with a denial of service attack targeting X’s infrastructure at scale,” he added.

Musk has previously claimed that the platform has been targeted by DDoS attacks, but these have not been confirmed.

Like all major social networks, X is a regular target for disruptive and attention seeking attacks.

But X has a track record of falling due to these attacks much more than other larger sites like Facebook and Instagram.

In 2023, a small group of hackers called Anonymous Sudan took the site offline in more than a dozen countries for hours in an attempt to pressurise Elon Musk into launching his Starlink service in their country.

Two men were arrested in 2024 for being the ringleaders of the group – showing that hackers can disrupt X with DDoS attacks from anywhere in the world with the right tools and expertise.

Cyber specialists are seeing a “sharp rise” in DDoS attacks which are becoming “an increasingly popular tool” for criminals, according to Sian John, chief technology officer at cyber security company NCC Group.

“Businesses that store large amounts of sensitive data, like tech firms, financial institutions, and healthcare providers, are frequent targets,” she said.

“But any organisation with an online presence is at risk.”

The body, eSafety, said it “noted with great sadness” that Rudakubana viewed the violent footage of the attempted murder of Bishop Mar Mari Emmanuel.

It said other major tech firms complied with its request to take the video down, but X – owned by Elon Musk – only blocked it in Australia, meaning Rudakubana was able to view it minutes before leaving his home to carry out his deadly attack.

The 18-year-old has been sentenced to a minimum of 52 years for the murders.

X has been contacted for comment.

Police officers who investigated last July’s Southport murders – which sparked riots across England – discovered a number of devices during a search of the 18-year-old’s home in Banks, Lancashire.

They have said it could take years to uncover what was in Rudakubana’s internet browsing history, which he deleted before he left the house to carry out his attack.

A search on X for the stabbing of the bishop was the only thing that remained, police have said.

He was attacked in the Sydney suburb of Wakeley in April 2024 – an incident deemed an act of terror by the police.

The attack on the bishop during mass at the The Good Shepherd Church sparked unrest in the Australian city.

After the attack on the bishop, which was livestreamed, eSafety said it worked “collaboratively where possible” with technology companies to remove the video from platforms.

“Immediately following the Wakeley attack, companies including Google, Microsoft, Snap and TikTok acted quickly to cooperate with eSafety and ensure the Wakeley stabbing video could not be accessed from their platforms,” the regulator said.

“Some of these companies took additional, proactive steps to reduce further spread of the material.”

eSafety subsequently contacted Meta – owner of Facebook and Instagram – and X, telling the companies to remove the material “under the provisions of Australia’s Online Safety Act”.

Meta did respond and took action which was welcomed by eSafety, but X decided to not remove the video from its platform, it said.

Instead, according to the regulator, X geoblocked the footage in Australia, meaning people outside the country and those within it using a VPN could still watch it.

In June last year, eSafety abandoned a legal battle to have the footage removed.

X has not responded to the BBC’s request for comment.

The tech mogul – and close confidant of US President-Elect Donald Trump – offered no immediate explanation for the name or his new profile image which depicts the character Pepe the Frog – a meme that has been used by far-right groups.

The move has sent ripples through the cryptocurrency world, sending the value of a memecoin – a digital currency inspired by internet memes – that shares the same name skyrocketing.

In the past, Mr Musk has influenced crypto prices with his social media commentary, but it was not immediately clear if he had any involvement in this particular memecoin.

“Kekius” appears to be a Latinisation of “kek”, a word roughly equivalent to “laugh out loud” popularised by gamers but now often associated with the alt right.

“Kek” is also the name of the ancient Egyptian god of darkness, who is sometimes depicted with the head of a frog.

Many people would link “Maximus” to the name of Russell Crowe’s heroic character in the film Gladiator, Maximus Decimus Meridius.

Mr Musk’s new profile image depicts Pepe in Roman military dress holding what appears to be a game console.