The northern oil hub is plagued with tensions among its rival Kurdish, Turkmen and Arab communities.

Assailants gunned down Bassem Abbas al-Bayati, a policeman of Turkman origin, as he returned home on Saturday in the centre of the city, said Lieutenant Colonel Kamel Ahmad.

A Kurdish peshmerga fighter, Karwan Jumaa Hussein, was killed the same way in northern Kirkuk, and two Sunni brothers, Shehab and Bilal al-Mufurdji, were shot dead in an eastern district of the city late on Friday.

Meanwhile, an Iraqi general said a man had been arrested in connection with a Tuesday attack at a market in Kirkuk that killed 33 people and wounded 92.

Mehdi Saleh Khalil is also suspected of involvement in a car bomb attack on April 15 that killed at least 10 police officers and wounded 22 others, said General Abdul Amir Reza Mohammed al-Zaidi.

Police said they had also distributed a leaflet offering a 2,500 dollar reward for information relating to an Al-Qaeda figure named Hawas Manaa Salah Al Assafi. Also known as Abu Qutaiba, he is suspected of involvement in a massive truck bomb that killed 72 people and wounded 200 south of Kirkuk on June 20.