BAGHDAD, Iraq, May 12, SPA -- A U.S. soldier fired on his fellow troops at a counseling center at a base outside Baghdad on Monday, U.S. officials said, killing five people in the worst such attack of the six-year war. The shooting occurred at 2 p.m. at a stress clinic at Camp Liberty, near Baghdad's international airport, two senior defense officials said. Though initial reports indicated the attacker was killed in the incident, the U.S. command in Baghdad said late Monday that a suspect in the killings was in custody. "Any time we lose one of our own, it affects us all," Col. John Robinson, a U.S. military spokesman, said in a written statement. "Our hearts go out to the families and friends of all the service members involved in this terrible tragedy." Neither the suspect nor any of the victims had been identified, but a defense official with access to the latest reports on the incident told CNN that the suspect had been a patient at the treatment center. "Preliminary reports show the soldier was being escorted to the clinic, for reasons not yet explained," an Army official, who spoke on condition of anonymity, told the Army Times.--SPA www.spa.gov.sa/663404