Two men dressed as women smashed a stolen car into a police vehicle and one was killed after they disobeyed commands at the closely guarded gates of the National Security Agency on Monday, prompting police to open fire.

The surviving man was wounded and was taken to a hospital. Details remained unclear hours later. Initial images from the scene showed emergency workers loading a uniformed officer into an ambulance. Nearby were a dark-colored SUV and an SUV emblazoned with “NSA Police,” both heavily damaged.

It was not known why the men wound up at the gate at Fort Meade, a sprawling military post that houses the National Security Agency, or why they did not obey orders from NSA police. Fort Meade is just off Interstate 295 between Baltimore and Washington.

Also unknown was why the men were dressed as women, said a senior defense official who spoke on condition of anonymity because the official was not authorized to discuss an ongoing case.

The NSA said in a news release that investigators had not yet determined the cause of death for the man who was killed, and the conditions of the wounded man and officer were not disclosed.

An agency officer gave the driver “routine instructions for safely exiting the secure campus,” but the driver disobeyed them, the release said. The driver then accelerated toward a police vehicle blocking the road, and police opened fire.

An FBI spokeswoman said the incident was not believed to be linked to terrorism.

The car carrying the men had been stolen Monday morning from a hotel in Jessup, Md., said Mary Phelan, a spokeswoman for the Howard County Police Department. She declined to name the hotel, citing the ongoing investigation, or release any further details, referring all questions to the FBI.

A strip of hotels, motels and other businesses is less than 10 miles from Fort Meade in Jessup.

The FBI was investigating, and was working with the U.S. Attorney’s Office in Maryland to determine if federal charges were warranted, FBI spokeswoman Amy J. Thoreson said in an email.

It’s not the first time someone has disobeyed orders at an NSA gate. In July, a man failed to obey an NSA officer’s command to stop as he approached a checkpoint. The man drove away, injuring an NSA officer and nearly striking a barricade. He was later arrested.

Earlier this month, police captured a man accused of firing at a building on the NSA campus. The man, who was also accused of shooting at vehicles, told police he heard voices.

Fort Meade also is home to the Defense Information Systems Agency and the U.S. Cyber Command. About 11,000 military personnel and about 29,000 civilian employees work on the property.

Jon Reinach, owner of Fort Meade Auto Center, said people sometimes stop by his service center asking for directions. Truck drivers sometimes also have to drop off their assistants at his shop because they don’t have proper identification to get past security.

“A lot of people come in here trying to find their way to Fort Meade,” Reinach said, adding that he’s heard of people going through the wrong security entrance, but “usually they’ll pull over to a waiting area and they usually do check out.”