Gunmen broke into the city council of Samarra city in Iraq's Salahudin province after blowing up a car bomb at the entrance, a provincial police source told Xinhua on Tuesday.

The attack occurred on Tuesday morning when gunmen wearing explosive vests attacked the city council building in Samarra, some 120 km north of Baghdad, after fierce clashes with the guards, the source said on condition of anonymity.

The gunmen apparently seized a number of workers and civilian hostages inside the building, the source said, adding that there is no immediate reports about casualties.

Reinforcement troops surrounded the city council and are preparing to storm the building, the source said.