Chinese hackers are being suspected to be behind the government’s Office of Personnel Management (OPM) coordinated hack attack.

According to a Wall Street Journal report, the attackers stole personal data of as many as 4 million people, but the OPM says the losses could be even more.

In a statement OPM says that it discovered the breach in April, and became sure that the records had indeed been stolen in early May.

The FBI and the Department of Homeland Security are investigating.

“We take very seriously our responsibility to secure the information stored in our systems, and in coordination with our agency partners, our experienced team is constantly identifying opportunities to further protect the data with which we are entrusted,” OPM director Katherine Archuleta told the WSJ.

Last week hackers accessed the servers at the Internal Revenue Service and stole data from as many 100,000 taxpayers.

The servers were accessed through an online service provided by the IRS and took financial data related to users’ actual tax returns.

Via VB