Hackers took over Donald Trump Jr.’s Twitter account Wednesday morning to post several sensational tweets, including a claim that his father, former US President Donald Trump, had died.

“I’m sad to announce, my father Donald Trump has passed away. I will be running for president in 2024,” posted the account, which has over 10 million followers.

The tweets have since been deleted. Former President Trump also posted several times on his own social network, Truth Social, since the tweet about his purported death was posted.

“Don's account has been hacked,” added Republican strategist and Trump Jr. spokesman Andrew Surabian in his own tweet.

The hackers also used Trump Jr.'s account to post “This just in: North Korea is about to get smoked,” and “Some interesting messages with Jeffrey Epstein,” a reference to the convicted sex offender, who died in prison.

It remains unclear how hackers took over his account. But in other high-profile hijackings, such as Twitter’s former CEO Jack Dorsey, the attackers resorted to using a SIM swap to gain access. This often involves the culprits tricking the cellular carrier into cloning the victim’s mobile phone number to a new SIM card, which can then be placed in their own phone.

The phone number can then often be exploited to initiate a password reset for any online account to which it's been registered. That's what happened to Ethereum cofounder Vitalik Buterin, who also suffered a SIM swap attack earlier this month, which allowed the attackers to hijack his Twitter account.

“A phone number is sufficient to password reset a Twitter account even if not used as 2FA (two-factor authentication),” Buterin said at the time.

Twitter and Trump Jr.’s office didn’t immediately respond to a request for comment.