Social media platform X was down for thousands of users in the United States and UK on Monday, according to Downdetector.

There were more than 23,210 reports of issues with X as of 8:24 a.m. ET (1324 GMT), according to Downdetector, which tracks outages by collating status reports from a number of sources.

X did not immediately respond to a request for comment on what caused the outage.

The actual number of affected users may differ from what’s shown on Downdetector because these reports are user-submitted.