WASHINGTON: A shooting at the metro entrance to the Pentagon left two police officers and a civilian suspect wounded, forcing a security lockdown at the US military headquarters.

"A shooting did occur. Two Pentagon force protection officers were injured. A suspect as well was injured," said spokeswoman Commander Wendy Snyder. "All three were taken to a local hospital."

The Pentagon later lifted the security lockdown and reopened its entrances after deciding that the danger had passed.

The injuries to the two officers "do not appear to be life threatening," the Defense Department said in a statement.

"The suspect was injured in return fire from the Pentagon Force Protection Agency officers," it said in a statement.

The suspect was "in custody and his condition is unknown."

The shooting occurred at 6:40 pm (2340 GMT) along a sidewalk adjacent to the metro station and the entrance to the Pentagon, officials said.

After the Pentagon was struck by a hijacked plane in the September 11 attacks of 2001, the building was fortified and elaborate security measures were imposed.

Metro riders take an escalator up from the underground station and then pass through a security check outside the building before entering the Pentagon and submitting to more security checks.

Besides serving the Pentagon and its vast workforce of military and civilian employees, the station is a major transportation hub for bus services into suburban northern Virginia.

After the incident, metro trains were moving through the station without stopping.

Metro authorities said Pentagon officials were also investigating "suspicious packages" outside the station but defense officials could not confirm the report.

The shooting occurred hours after Danish Defense Minister Gitte Lillelund held talks at the Pentagon with US Defense Secretary Robert Gates to discuss the NATO-led war effort in Afghanistan.