The Washington Post is investigating a cyberattack on its journalists' email accounts, according to news reports.

The Post's executive editor, Matt Murray, said in a memo to employees of the newspaper that the breach was discovered Thursday and the newspaper immediately initiated an investigation, Reuters reported after reviewing the memo.

He also said Post employees had their passwords reset Friday as a precaution and that the cyberattack was not believed to have had any impact on any additional Post systems or customers. There was also a credential reset for all Post employees on Friday night.

The cyberattack was potentially from a foreign government, according to The Wall Street Journal. 

Post employees were told that the breach compromised journalists' Microsoft accounts and could have granted the attacker access to work emails. The journalists whose emails were targeted included those on the national security and economic policy teams, including some who write about China.