BAGHDAD , Iraq ( CNN ) -- Five U.S. soldiers were killed Friday in a suicide bombing in the northern Iraqi city of Mosul -- the single deadliest attack on U.S. troops in more than a year , the U.S. military said . A suicide truck bomber breached the outer security barrier of Iraqi National Police headquarters in southern Mosul , and detonated his explosives , killing eight people and wounding 60 others , an Iraqi Interior Ministry official said . A U.S. soldier was also among the wounded , the U.S. military said . The ministry said those killed include five Americans , two Iraqi policemen and an Iraqi soldier . At least two individuals suspected of being involved in the attack were detained , the U.S. military said . It is the deadliest attack on U.S. forces since March 10 , 2008 , when five U.S. soldiers were killed in a suicide attack in Baghdad . Despite a number of military operations in this volatile city during the past year , Mosul remains one of the most violent places in Iraq . Last year the U.S. military said Mosul was the last urban stronghold of al Qaeda in Iraq . Mosul is the provincial capital of Nineveh and is about 260 miles , or 420 kilometers , north of Baghdad . Watch a suicide bomb attack kills 5 U.S. soldiers » . U.S. and Iraqi military forces plan to pull out of Mosul to allow Iraqi police to control security in the city . But police are not quite ready yet , according to an Iraqi general . `` We need to bring the police to the required level . The deadline is the end of July , and it 's not enough time to prepare the police , '' said Gen. Hassan Karim , commander of Nineveh operations for the Iraqi army . `` ( That ) means we 'll need U.S. forces to stay in Mosul . '' CNN 's Nic Robertson contributed to this report .
NEW : Attack is deadliest on U.S. forces in more than a year . Suicide bomber explodes truck at national police headquarters in Mosul . Five Americans among eight dead ; 60 others wounded . Score: 6