The Chinese government news agency Xinhua, citing a police source, said four militants wearing suicide vests stormed the city council after exploding a car bomb outside. They killed five people and wounded at least 48, including three members of the council, the police official said.
After government troops entered the building, the four bombers blew themselves up, Xinhua said.
Tikrit, about 100 miles north of Baghdad, was Saddam Hussein's birthplace. The city is the capital of the Sunni-majority Salahudin province and a center of opposition to the current Iraqi government.