So far, there's no evidence any information was stolen.
Twitter TWTR is reportedly warning some of its users that their accounts may have been “targeted by state-sponsored actors” looking to steal personal information ranging from email addresses to phone numbers.
Canadian coding nonprofit Coldhak tweeted an image of the email it received from Twitter Monday morning. The note warns that government hackers may have targeted “a small group of accounts,” though the social media site said it had found no evidence that hackers successfully stole any user information. “We wish we had more we could share, but we don’t have any additional information we can provide at this time,” Twitter said in the email.
Twitter confirmed to the Financial Times that it sent the notices to some users but did not comment further. The company did not immediately respond to Fortune‘s request for comment.
In October, Facebook FB posted a public message informing its own users that it would notify them at any point in the future when it believes their accounts may have been “targeted or compromised” by state-sponsored attackers. And, last month, Google GOOG made a similar announcement when the search giant said it would notify users when they receive emails through unsecure connections.
Twitter’s message also did not specify where the potential state-sponsored attacks might have originated. In the past, though, countries like China and North Korea have been suspected of supporting high-profile hacks such as this year’s cyberattack on the U.S. Office of Personnel Management as well as the infiltration of Sony’s computer system last year. The Syrian Electronic Army has also claimed responsibility for hacking various high-profile Twitter accounts in the past.