FORT MEADE, Md. (AP) -- Two men dressed as women smashed a stolen car into a police vehicle after they disobeyed commands at the closely guarded gates of the National Security Agency on Monday, prompting police to open fire.

One of the men died, the other was injured and a police officer also was taken to a hospital. Details remained unclear hours later. Initial images from the scene showed emergency workers loading the 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.

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. It also was unclear exactly what the men were wearing.

The NSA said in a news release that investigators have not yet determined how the man in the vehicle died, 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 then opened fire.

An FBI spokeswoman said earlier in the day that the incident was not believed to be linked to terrorism. The NSA said the incident was contained to the perimeter of the secure campus.

The car that rammed the police vehicle had been stolen Monday morning from a hotel in Jessup, Maryland, 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.