BAGHDAD (AFP) - As many as five suicide bombers killed 12 people on Sunday at an Iraqi army complex, the military said, in the first major strike in Baghdad since the US army declared an end to combat operations last week. The coordinated attack occurred in the morning at the rear gate of Rusafa military command headquarters in the centre of the capital, which only three weeks ago was hit by a massive suicide bombing that killed dozens. Accounts varied between witnesses and security force members, but the capitals security command said five suicide attackers had approached the compound in a minibus. One of them stepped out of the minibus, and security forces fired at him and he exploded, Baghdad operations command said in a statement. Two others fled to a nearby building, and the minibus exploded with the two remaining terrorists inside. Security forces cordoned off the building and traded fire with the last two terrorists until both of them blew up. Baghdad operations command, which is also based in the complex that was attacked, put the toll at 12 dead and 36 wounded from the attack. A Defence Ministry official, speaking on condition of anonymity, said that 11 people had been killed. It was unclear how many of the victims were soldiers. I was waiting with three of my colleagues near an armoured car (when the attack occurred), a policeman told AFP on condition of anonymity from the hospital, slumped against the wall of the emergency room with bandages covering gunshot wounds to both of his legs. The largest blast sent plumes of smoke into the skies over the capital, with nervous soldiers frisking any civilians who crossed Bab al-Muatham bridge, which connects the west side of Baghdad to Rusafa in the east. The explosion caused extensive damage to nearby buildings and Dr Adil Saloom, director of the hospitals emergency department, said 20 patients had been treated. Adil Kadhim, an emergency room nurse, said most of the victims had suffered fractures, gunshot wounds and trauma. US troops fired on insurgents who attacked the complex, a US army spokesman told AFP, the first such engagement in the capital since American forces declared an end to combat operations four days ago. Lt-Col Eric Bloom said an American team of advisors had been stationed at the complex, an old defence ministry compound, and when the attack occurred, their security team provided suppressive fire.