Elon Musk claims the wave of outages affecting X is due to a “massive cyberattack.”

Elon Musk’s social network X was hit by waves of outages on Monday, which the billionaire claims were due to a cyberattack using IP addresses originating in Ukraine.

“We’re not sure exactly what happened,” Musk said during an interview with Fox Business on Monday afternoon. “But there was a massive cyberattack to try to take down the X system, with IP addresses originating in the Ukraine area.”

Musk did not elaborate on the source of the attack, including whether he believes it was connected to the Ukrainian government. It is possible to mask IP addresses and make traffic appear to be coming from elsewhere, and spoofing locations is often offered by hackers for hire.

According to the outage tracking site DownDetector, the problems began around 6 a.m. (Miami time) when up to 20,538 users reported issues. The issues temporarily subsided before nearly 40,000 users reported outages at 10 a.m. Since 12:30 p.m. (Miami time), there have been approximately 26,000 reports at the time of writing.

Many users on DownDetector complained that the app was not loading, and the outage appears to be global, according to DownDetector’s international sites.