The cyberattack on the Marriott hotel chain that collected personal details of roughly 500 million guests was part of a Chinese intelligence-gathering effort that also hacked health insurers and the security clearance files of millions more Americans, according to two people briefed on the investigation.

The hackers, they said, are suspected of working on behalf of the Ministry of State Security, the country’s Communist-controlled civilian spy agency. The discovery comes as the Trump administration is planning actions targeting China’s trade, cyber and economic policies, perhaps within days.

Those moves include indictments against Chinese hackers working for the intelligence services and the military, according to four government officials who spoke on the condition of anonymity. The Trump administration also plans to declassify intelligence reports to reveal Chinese efforts dating to at least 2014 to build a database containing names of executives and American government officials with security clearances.