BAGHDAD, Iraq (CNN) -- Six Iraqi police officers were killed and 12 others wounded Friday in a gunbattle at a checkpoint north of Baghdad, police and hospital officials said. At least 40 gunmen in three vehicles began shooting at the checkpoint near the town of Baquba about 7:30 a.m. (11:30 p.m. ET Thursday), officials said.The battle continued for about 30 minutes, with the attackers using small-arms fire, according to authorities.The commander of the checkpoint in Buhriz, about 7 kilometers (4 miles) south of Baquba, was among those killed, officials said. A roadside blast in the southern Baghdad neighborhood of Dora killed one person and injured eight others, police said.The bomb hit a civilian vehicle, they added.U.S.: Suspected insurgents killedThe U.S. military on Friday said it had identified five people killed last Saturday as suspected al Qaeda leaders.Authorities initially said several suspected terrorists were killed in the October 29 strikes in Husayba, near the Syrian border, which were part of a series of raids on suspected terrorist safe houses.Three safe houses were destroyed by air strikes, the military said. One apparently was the location of a meeting between suspected al Qaeda in Iraq terrorist leaders from the Husayba and Qaim areas west of Iraq, coalition forces said in a written statement Friday.The military said those killed included: Abu Asil, a suspected North African terrorist who was a senior al Qaeda in Iraq foreign fighter facilitator in the Qaim region and was a suspected associate of wanted militant Abu Musab al-Zarqawi.Abu Raghad, a senior al Qaeda in Iraq foreign fighter and terrorist cell leader who operated in the Husayba area.Abu Talha, an al Qaeda in Iraq terrorist cell leader in the western Ubaydi area.Abu Usama and Abu Salman, al Qaeda in Iraq terrorist cell leaders in the Husayba area.2 more U.S. soldiers killedA U.S. soldier died Thursday night near Tallil from non-battle-related causes, a U.S. military statement said. Authorities are investigating the incident near Nasiriya in southern Iraq.The military also reported that another U.S. soldier in Baghdad was killed Friday. The soldier, assigned to Task Force Baghdad, was killed when a convoy struck a roadside bomb on the eastern side of the capital, the military said. The names of both soldiers were being withheld until their families are notified. Since the start of the war, 2,039 U.S. troops have died in Iraq.