Twitter, already under fire from lawmakers and regulators, appeared to go down altogether on Thursday.
An unknown number of users were unable to access the social network's website and mobile apps, with tracking website Downdetector recording more than 57,000 reports by 6 p.m. ET. That dropped to a few hundred by 9 p.m. ET.
Twitter said Thursday evening that the issue was "caused by an inadvertent change we made to our internal systems."
"Twitter should be working for everyone within the next few hours," the company said around 8 p.m. ET.
The disruption comes a few months after a massive hack of some of Twitter's biggest accounts, including those belonging to Barack Obama, Joe Biden, Jeff Bezos and Kim Kardashian West, which regulators in New York this week said originated in a tech support scam.
Twitter, Facebook and other social media platforms are under increased pressure to prevent their platforms from being compromised ahead of the November 3 US election, while also clamping down on disinformation and conspiracy theories. The companies are also being pressed to do more to regulate content that appears on their platforms, with the Federal Communications Commission (FCC) gearing up to draft regulations intended for social media companies following a petition earlier this year by the Trump administration.