(Adds second attack)
BAGHDAD, Dec 3 (Reuters) - Twelve people were killed in two separate attacks targeting a government complex and a police building in Iraq on Tuesday, police and medics said.
No group immediately claimed responsibility for the attack, but Sunni Muslim insurgents have regularly hit targets linked to the Shi'ite-led government and security services since the start of 2013, amid the country's worst spate of violence in five years.
In the first assault, nine people were killed and 17 wounded in a suicide and mortar attack on a government compound in the northern Iraqi town of Tarmiya, around 25 km (15 miles) north of Baghdad.
One attacker wearing an explosive belt blew himself up at the structure, which held the mayor's office, the town's police station and other government organisations, officials told Reuters.
Others shot at security guards and fired mortars at the compound.
Four members of the security services were killed in the second attack on a police adminstrative building in the northern city of Tikrit when a car bomb exploded near the main gate. Some 19 people were wounded, including civilians.
Three people wearing explosives and military uniforms drove to the gate in SUVs after the car bomb. Two detonated themselves and one was killed by police.
Violence in Iraq, sometimes carried out by groups linked to al Qaeda, has been exacerbated by the increasingly sectarian conflict in neighbouring Syria. (Reporting by Kareem Raheem in Baghdad and Ghawan Hassan in Tikrit, Writing by Raheem Salman; Editing by Ralph Boulton)