the details were added (the first version was posted at 15:05)
At least 30 people were killed in a double bombing targeting the offices of a Kurdish political party in the northern Iraqi town of Tuz Khurmato on Monday, local officials and medical workers said.
Security sources said a car bomb blew up at a checkpoint near the local headquarters of the Patriotic Union of Kurdistan (PUK) party, before a truck packed with explosives was detonated beside a wall, Reuters reported.
The attack is the latest in a show of strength by militants who have been regaining ground in Iraq and on Sunday killed 18 people in twin blasts targeting PUK offices in the town of Jalawla.
The Sunni militant Islamic State in Iraq and the Levant (ISIL) said it was behind that attack and also claimed responsibility for the bombing on Monday, crediting a suicide bomber whose name indicates he was Egyptian.
A further 185 people were wounded in the blasts, the force of which destroyed many buildings in the area. Sources said more bodies were likely to be found beneath the debris.
A 55-year old man who was being rushed to hospital in the city of Kirkuk on a stretcher, his white robes drenched with blood, said he was returning from the market in Tuz Khurmato when one of the bombs exploded around 200 metres away from him.
"The wall of one of the houses nearby fell on me. It hurt my back and my legs. I started screaming and people came to my rescue and pulled me out from under the collapsed wall. All my limbs were broken."
Tuz Khurmato is around 170 km (100 miles) north of the capital Baghdad and lies in territory which both the federal government and the autonomous Kurdistan region claim as theirs.
Both are a target for Sunni Islamist insurgents who in recent days overran two major cities, occupied a university campus in western Iraq and set off a dozen car bombs in Baghdad.
Nearly 800 people were killed across the country in May alone - the highest monthly toll this year so far - and last year was Iraq's deadliest since violence began to ease from a peak in 2006-07.
Traffic policeman Ahmed, whose body was covered in shrapnel wounds, was taken to Kirkuk hospital in a car by his colleagues and was still wearing his uniform.
"It was like Doomsday. There was smoke filling the air. I fell to the ground due to the power of the explosion and my colleagues were shouting asking me not to move because I was badly hurt. I saw many bodies on the ground."