A suicide bomber blew up a fuel truck outside a police centre in the Iraqi city of Mosul on Thursday and rebels fired mortars and fought gunbattles with police across the city in violence that killed 20 people. Another U.S. soldier was killed in combat, the U.S. military said, a day after it announced the deaths of 11 U.S. soldiers in one of the bloodiest days in the war for U.S. troops. At least 71 U.S. troops have been killed so far in October, putting the month on track to become one of the deadliest for U.S. forces since a massive offensive in Falluja two years ago. The blast in Mosul, a flashpoint of Sunni Arab insurgents north of Baghdad, killed 11 people and wounded 26. Nine charred bodies lay on the debris-strewn streets. Shortly after the explosion, insurgents fired mortar shells at another police centre and clashed with police. Nine more people were killed in the violence. The governor imposed a curfew and Iraqi forces were patrolling the city, a Reuters reporter in Mosul said.