IS militants unleashed multiple suicide attacks in the city of Tikrit, north of Baghdad, killing at least 22 people, a provincial official said on Wednesday. Five suicide bombers on foot targeted a police patrol and broke into a police officer's house in Tikrit's al-Zihoor neighbourhood, according to a Salahuddin provincial council member, Ahmed al-Karim. Al-Karim told The Associated Press that security forces managed to kill three of the bombers while two blew themselves up. Ten policemen were among the dead and up to 31 people were wounded in Tuesday night's attacks, he added. No group immediately claimed responsibility for the bombings but IS militants have carried out scores of similar attacks to detract from the fighting in Mosul, Iraq's second-largest city. The Sunni extremist group frequently targets Iraqi security forces and civilians in urban areas. Iraqi forces drove out IS militants from Tikrit in April 2015. Since then, IS militants have launched a number of big attacks in and around Tikrit, located about 80 miles (130 kilometres) north of Baghdad. IS has suffered a string of defeats over the past two years — most recently in the Mosul operation where Iraqi forces, backed by a U.S.-led coalition are battling to drive the extremists out of the western part of the city, a more densely populated area. Eastern Mosul, which is separated by the Tigris river from the western part of the city, was declared liberated from IS in January. Despite the severe setbacks, the IS group has managed to regularly launch attacks in some Iraqi cities. A series of large-scale bombings claimed by IS has also struck Baghdad since the operation to retake Mosul began in October. Iraqi and U.S.-led international coalition officials have repeatedly warned that after Mosul, IS will likely return to its insurgent roots as it loses more territory in both Iraq and neighbouring Syria.