Insurgents killed six Iraqi police at a checkpoint Friday and fired a mortar round that struck a home outside the capital, killing a child, The Associated Press reported. Meanwhile, Al-Qaida in Iraq threatened more attacks on diplomats here. "We are renewing our threat to those so-called diplomatic missions who have insisted on staying in Baghdad and have not yet realized the repercussions of such a challenge to the will of the mujahedeen," said statement of Al-Qaida. Also Friday, the U.S. military said it had killed five senior al-Qaida figures in Iraq during an airstrike last Saturday in Husaybah near the Syrian border. The five, including at least one North African, were responsible for bombings against U.S. and Iraqi forces, the announcement said. Friday's worst attack by insurgents occurred at an Iraqi police checkpoint in Buhriz, 55 kilometers (35 miles) north of Baghdad. The insurgents fired mortar rounds, then arrived in eight cars and opened fire, a police officer said. At least six policemen were killed and 10 wounded in the ensuing gunbattle, and it was not immediately known if any militants were hurt, the officer said. On the outskirts of Baghdad, near the U.S.-run Abu Ghraib detention center, insurgents fired a mortar round that missed an American base but hit a village home, killing a child and wounding the mother and another one of her children, said police 1st Lt. Ahmed Ali. Suspected insurgents also shot and killed Tarijk Hasan, a former colonel in the Iraqi air force, as he drove through Baghdad on Thursday, said police Capt. Talib Thamir. Late Thursday, a U.S. soldier also died near Talil, 270 kilometers (170 miles) southeast of Baghdad, the military said. The death, apparently of non-hostile causes, brought to at least 2,038 the number of U.S. military service members who have died since the Iraq conflict began in March 2003, according to an Associated Press count.