Hackers have targeted Twitter, gaining “limited” access to around 250,000 user accounts, the social networking site announced on Friday.
“This week, we detected unusual access patterns that led to us identifying unauthorized access attempts to Twitter user data,” a blog post by Twitter’s director of information security said.
The post said hackers may have accessed “usernames, email addresses, session tokens and encrypted/salted versions of passwords.”
Twitter said it had already reset passwords for affected users, and will notify them soon.
The cyber attack comes days after US newspapers the New York Times and the Wall Street Journal revealed their respective websites had been the target of a well-coordinated hacking effort.
"This attack was not the work of amateurs, and we do not believe it was an isolated incident," Twitter said.
"The attackers were extremely sophisticated, and we believe other companies and organizations have also been recently similarly attacked."
The company did not specifically link the attacks to China in the blog post, in contrast to the newspapers, which both said the hackers originated in China.