Scores of users reported that they were sent password reset emails by the firm earlier today, sparking rumours of widespread hacking activity on the social network.
However, Twitter has now clarified that it "unintentionally" reset a large number of passwords after some accounts were compromised.
The company said in a statement: "We're committed to keeping Twitter a safe and open community.
"As part of that commitment, in instances when we believe an account may have been compromised, we reset the password and send an email letting the account owner know this has happened along with information about creating a new password. This is a routine part of our processes to protect our users.
"In this case, we unintentionally reset passwords of a larger number of accounts, beyond those that we believed to have been compromised. We apologise for any inconvenience or confusion this may have caused."
Twitter did not reveal how many users were affected or the source of the hack, but it is thought that a third-party tool was manipulated to expose user passwords.