A gunman has died after opening fire and wounding two police guards outside the Pentagon entrance, dpa quoted police as confirming today. John Patrick Bedell, 36, pulled a handgun and started firing as he tried to enter the Defence Department's headquarters Thursday evening, according to Pentagon Police Chief Richard Keevil. Bedell was wounded in the shootout and died of his injuries a few hours later. Two Pentagon civilian police officers were hospitalized with what Keevil described as "grazing injuries," which were not life threatening. Bedell is believed to have acted alone and Keevil said police had yet to find a motive. Investigators were looking into internet postings from Bedell, originally from California, that reportedly displayed anger towards the US government and skepticism over the September 11, 2001, attacks. The incident began about 6:40 pm (2340 GMT), when Bedell approached the sprawling office complex's busy entrance at the Washington Metro's Pentagon station. He was "very calm" and reached into a pocket for what the officers at the checkpoint expected would be a pass to enter the building but instead pulled out a handgun and shot the two officers, Keevil said. "Both officers were able to return fire," he said. The officers, armed with .40-calibre semiautomatic Glock handguns, wounded and disabled the suspect. "Many" shots were fired, Keevil said. "We were fortunate that there (were) no other injuries," he said. The officers at the scene, Jeffery Amos and Marvin Carraway, described the suspect as showing no distress or nerves and not speaking before the shooting: "He walked up very cool," Keevil said. Pentagon police were being assisted in the shooting investigation by FBI and Secret Service agents and sheriff's deputies from Arlington, Virginia, where the defence headquarters are located on the Potomac River across from Washington. The Pentagon was locked down for at least an hour after the shooting, and the Pentagon subway station was closed, delaying trains during the later part of the Thursday evening rush hour.