The U.S. Central Intelligence Agency pulled a number of officers from the U.S. Embassy in Beijing after federal personnel records hacked, Washington Post reported, citing current and former U.S. officials.

With CIA declining to comment, the number of CIA officers previously deployed in Beijing Embassy is still unknown.

Earlier this year, two massive data breaches at the U.S. Office of Personnel Management were reported, exposing 21.5 million personnel records of current and former U.S. federal employees. The U.S. seemed to fear that China could have compared those records with the list of embassy personnel. Any name not on that list can be a CIA agent, Washington Post reported.

There was an in-depth discussion on the issue of cyber security during President Xi Jinping's state visit to the U.S., which produced important consensus. China Ministry of Foreign Affairs spokesman Hong Lei said on Wednesday, “The Chinese government firmly opposes and cracks down on all forms of hacking activities in accordance with the law.”