Insurgents in Iraq have unleashed a series of attacks in several cities.

Authorities in Iraq say at least 17 people were killed Thursday in car bomb attack in central Baghdad. Police say the explosion in Nasr Square, a densely populated commercial area, targeted a police patrol.

Meanwhile, in the northern city of Mosul, insurgents raided several police stations, stealing weapons and torching buildings.

Elsewhere, insurgents detonated a car bomb in the northern Iraq province of Kirkuk, in an apparent attempt to assassinate the provincial governor.

Hospital officials say at least 12 people were injured in the attack. The Kirkuk governor, Abdulrahman Mustafa, escaped unharmed.

Insurgents have stepped up attacks on security forces across the country in the past week as the government launched a major ground offensive to retake the rebel-held city of Fallujah.

Some information for this report provided by AFP and AP.