Hackers tried to access user accounts on the U.K. Parliament's network Friday night.
House of Lords life peer Chris Rennard confirmed the attempt on Twitter, as did the House of Commons Press Office.
It wasn't immediately clear where the attack came from, but it followed a report from The Times that Russian hackers had gotten hold of government official's email addresses and passwords and traded them online.
Authorities are working with the National Cyber Security Centre to determine the method of the attack. Initial reports are that it was a "sustained and determined" attempt to access "all parliamentary user accounts" to find weak passwords.