A suicide car bomber targeted the provincial police headquarters in Mosul on Monday, killing at least nine people and wounding dozens, police said. The attack underscored fears that Sunni insurgents are regrouping despite a US-Iraqi offensive in the northern city. The attacker detonated his explosives-laden car about 8 p.m. as he approached a checkpoint allowing cars through concrete blast barriers surrounding the headquarters, which is located in a busy commercial district. Those killed included five policemen and four civilians, while 46 other people were wounded, according to a police officer, who spoke on condition of anonymity because he wasn't authorized to release the information. Nobody claimed responsibility for the attack, but suicide operations are commonly associated with of al-Qaida in Iraq - the main target of US-Iraqi military operations to clear the city. The US military has said the terror network is on the run but retains the ability to conduct its trademark high-profile car bombings and suicide attacks.