Iraqi officials say a suicide car bomber has exploded a vehicle outside a prison near Baghdad, killing 11 people and wounding at least 15 others.

The blast happened Monday morning at the entrance to the al-Hout prison in the town of Taji. Authorities say policemen, guards and civilian workers were among those killed.

The car bombing is the third major attack in Iraq in the past week. Bombings and shootings in and around Baghdad killed at least 15 people Saturday, while a triple bombing in the southern city of Basra killed at least 19 people Thursday.

Violence has declined across Iraq since a sectarian conflict peaked in 2006 and 2007, but deadly attacks remain common as U.S. troops prepare to leave the country at the end of this year.

Iraqi authorities say 258 people were killed in violence in October, including civilians and security personnel. U.S. and Iraqi officials have said insurgents may intensify attacks in the final stage of the U.S. military pullout to take advantage of a perceived power vacuum. But, they say Iraqi forces will be ready to deal with the country's security problems on their own.