At least fifteen people have been killed and more than 100 injured after a suicide bomber blew himself up in the Iraqi city of Kirkuk, apparently targeting an office of the Kurdistan Democratic Party. The attack on Wednesday struck in the centre of the ethnically-mixed northern city, where the attacker detonated a car bomb. The blast appeared to target a compound housing local offices of the Kurdistan Democratic Party of Kurdish regional president Massud Barzani. Police sources also confirmed that another suicide car bomber attacked in the town of Tuz Khurmatu, south of Kirkuk, killing two people and injuring 26 others. The second explosion took place near the headquarters of the Patriotic Union of Kurdistan. No group immediately claimed responsibility for the attack. The violence comes amid a political crisis that has pitted Prime Minister Nouri al-Maliki against several of his ministers just months ahead of provincial elections, a barometer of support for Maliki and his opponents ahead of a general election next year.