Three suspected insurgents fled a jail in the western city of Ramadi on Friday morning after overpowering guards, Iraqi officials said. The jailbreak led to a gunfight in which six policemen and seven suspected insurgents were killed, authorities said. Iraqi security forces launched a manhunt for the three escapees, who officials said included a top leader of the Sunni insurgent group al-Qaeda in Iraq. The jailbreak comes as U.S. officials are shutting down their detention facilities across the country and as American troops are sharply reducing their presence in Anbar province, a predominantly Sunni territory that was the cradle of the insurgency. Ramadi is the capital of Anbar. The incident occurred at 3:30 a.m. as guards were escorting a group of inmates from an interrogation room to a cell, said Maj. Gen. Tariq al-Duleimiy, the Ramadi police chief. He said a suspected insurgent told authorities that the operation had been planned out. "The plan was to grab a weapon from the guards" in order to flee, he said. "We hope to capture those three very dangerous criminals." Lt. Col. Abdul Ghani al-Duleimiy, the chief of the jail, was among those killed in the shootout, Iraqi officials said. Iraqi officials imposed a curfew in Ramadi, limiting vehicle and pedestrian traffic as they searched for the suspected insurgents, who were believed to have fled on foot. The police chief said Iraqi and U.S. troops had fanned out across the area to look for the men in neighborhoods and orchards. In recent months, U.S. officials have released tens of thousands of detainees. U.S. officials will lose the authority to detain Iraqis without formal charges beginning Jan. 1, when a security agreement between Iraq and the United States will replace the United Nations mandate that has given the U.S. government vast power since the 2003 invasion. Security in Anbar, the deadliest province for U.S. troops outside of Baghdad, has improved dramatically in recent months as tribes and groups of former insurgents have turned against hard-line insurgent groups.