“Chinese nationals, sometimes posing as tourists, have accessed military bases and other sensitive sites in the U.S. as many as 100 times in recent years, according to U.S. officials, who describe the incidents as a potential espionage threat,” the Wall Street Journal wrote in a weekend report.

DOD, the FBI and other agencies held a review last year to try to limit the “gate crasher” incidents, the story said. Officials said the individuals are likely tasked with testing security at U.S. federal sites and reporting back to the Chinese government.

Rep. Jason Crow (D-Colo.) said Congress may look into it and whether cases are falling through the cracks because most trespassing laws are state and local.

“We need to work closely with our state and local partners to train them and equip them,” Crow said. “Right now, they don’t know how to deal with it.”

Military.com also has more on the report.

Air Force photo by Senior Airman Lauren Cobin