Facebook has fixed a bug today that disabled an unknown number of accounts, which appeared to belong to females, according to the complaints posted on the Web.

"Earlier today, we discovered a bug in a system designed to detect and disable likely fake accounts," a Facebook spokesperson said in an e-mail. "The bug, which was live for a short period of time, caused a very small percentage of Facebook accounts to be mistakenly disabled."

Facebook fixed the problem and was in the process of reactivating and notifying affected users, the statement said.

Complaints about the problems on Facebook and Twitter were from women, or from men reporting on the problem for a female friend or relative. Some people said they had been asked to scan in a government-issued ID to verify their identity in order to get their accounts re-instated.

"When we detect that an account may be fake, we ask the owner to verify his or her identity," the spokesperson said. "In very rare cases where no other form of verification is possible, we may ask the account owner to verify by providing a valid ID. This bug affected a system that uses this type of verification." The spokesperson declined to say how many or what percentage of its more than 500 million active users were affected or provide more details.

The problems come one day after Facebook unveiled a messaging system that will integrate different forms of messages from various platforms.

Facebook users, all seemingly female, complained about their accounts being disabled on Twitter.