Tech billionaire Elon Musk says his social media platform X has suffered a “massive cyberattack” after the service went down, leaving tens of thousands of users unable to access their accounts.

Complaints of outages spiked between 10:00 and 14:00 GMT on Monday, according to tracking website Downdetector.com, with more than 40,000 users unable to access the platform.

Speaking to X, Musk said the platform is targeted daily but the latest attack was “carried out with a lot of resources” and was orchestrated by a “large, coordinated group and/or country.” He did not provide evidence for his claim.