In a carefully worded , LinkedIn director Vicente Silveira said the company has confirmed that an unspecified number of hashed passwords posted publicly on a Russian hacker forum earlier this week, "correspond to LinkedIn accounts."

Silveira made no mention of how the passwords may have ended up on the forums but noted that LinkedIn is continuing to investigate.

"Members that have accounts associated with the compromised passwords will notice that their LinkedIn account password is no longer valid," Silveria said.

Users of the social networking site for professionals will also receive an email from LinkedIn with instructions on how to reset their passwords. The email will not contain any links that users will need to click on to reset their password, he noted. Affected customers will also receive a note from LinkedIn with more information on what happened and why they are being asked to reset their passwords, Silveira said.

Earlier Silveira had posted a separate note urging LinkedIn members to change their passwords and providing them with tips on how to create strong passwords.