Social media platform X is down for thousands of users in the U.S. and the UK, according to outage tracking website Downdetector.com.

There were more than 21,000 incidents of people reporting issues with the platform in the U.S. and more than 10,800 incidents in the UK, according to Downdetector, which tracks outages by collating status reports from a number of sources.

X did not immediately respond to a Reuters request for comment.

Downdetector’s numbers are based on user-submitted reports. The actual number of affected users may vary.