A bomb also exploded in the northern city of Arbil on Saturday, a rare attack unsettling the relative stability the capital of the semi-autonomous Kurdish region has enjoyed.
Local television footage showed firefighters dousing the charred remains of a car in Arbil. A Reuters journalist earlier saw a cloud of smoke, but the source was not clear.
In Baghdad, a bomber rammed a vehicle into an intelligence headquarters, killing at least eight people, police and medical sources said.
Near Tikrit, a suicide bomber driving a military Humvee packed with explosives attacked a gathering of soldiers and militias overnight, killing nine.