The British Parliament was the target of a “sustained” cyberattack as hackers sought to gain access to the email accounts of MPs and their staff.  The attack left the users unable to access their email as the hackers probed to identify email accounts with weak passwords.

Cybersecurity officials notified lawmakers regarding the hacking attempt on Friday, and took steps to block Parliament members from trying to access their emails remotely, outside of the secure network in Westminster.

The House of Commons is working with the National Cyber Security Centre to defend Parliament’s network, even as a spokesperson for the House of Commons confirmed the attack in a statement.

“The Houses of Parliament have discovered unauthorised attempts to access parliamentary user accounts. We are continuing to investigate this incident and take further measures to secure the computer network, liaising with the National Cyber Security Centre,” read the statement.

“We have systems in place to protect member and staff accounts and are taking the necessary steps to protect our systems.”

According to The Guardian, an email sent to “all those affected” further confirmed the cyberattack. “Earlier this morning, we discovered unusual activity and evidence of an attempted cyber-attack on our computer network. Closer investigation by our team confirmed that hackers were carrying out a sustained and determined attack on all parliamentary user accounts in an attempt to identify weak passwords.

“These attempts specifically were trying to gain access to our emails. We have been working closely with the National Cyber Security Centre to identify the method of the attack and have made changes to prevent the attackers gaining access, however our investigation continues.”