U.S. intelligence agencies traced a recent cyber intrusion into a sensitive infrastructure database to the Chinese government or military cyber warriors, according to U.S. officials.

The compromise of the U.S. Army Corps of Engineers’ National Inventory of Dams (NID) is raising new concerns that China is preparing to conduct a future cyber attack against the national electrical power grid, including the growing percentage of electricity produced by hydroelectric dams.

According to officials familiar with intelligence reports, the Corps of Engineers’ National Inventory of Dams was hacked by an unauthorized user believed to be from China, beginning in January and uncovered earlier this month.

This trend seems to be getting worse.