Twitter is having a major outage

Twitter‘s website was down Thursday afternoon, with users who tried to visit the service greeted by an error message.

A note on the company’s status website showed that Twitter was investigating an irregularity with its application programming interface, or API. The company’s mobile app also appeared to not be functioning properly.

The service appeared to have been at least partially restored for some users around 7 p.m. ET, after being down for more than an hour.

“Twitter has been down for many of you and we’re working to get it back up and running for everyone,” the company tweeted. “We had some trouble with our internal systems and don’t have any evidence of a security breach or hack.”

The outage comes one day after Twitter and rival Facebook made the unprecedented editorial decision to limit the reach of a New York Post story that claims to show “smoking gun” emails related to Democratic presidential nominee Joe Biden and his son Hunter Biden.

The company suffered a major service failure earlier this year when the Twitter accounts of some of the most famous people in the country were compromised as part of an apparent bitcoin scam in July. Victims included Joe Biden, former President Barack Obama and Tesla CEO Elon Musk.

A spokeswoman for the company acknowledged that it was looking into issues.

This story is developing, please check back for updates.