A police spokesman said Thursday night the Pentagon shooting suspect's nationality is American.

In a news briefing near the scene just outside Pentagon, police chief Richard Keebill told reporters the suspect is an American. He showed no emotion nor distress as he approached and shot the two police officers at around 6:40 p.m. (2340 GMT) in the Metro station outside Pentagon.

"He looked very cool," Keebill said.

The shooting took place earlier in the night. The wounded officers are with the Pentagon Force Protection Agency, according to Chris Layman, spokesman for the agency. He said they have one suspected shooter in custody.