At least 33 people have been killed in two suspected suicide attacks in the northern Iraqi town of Tal Afar, police have said.

The second bomber reportedly detonated his explosives as people gathered to help victims of the first blast on Thursday.

More than 70 people were reportedly wounded.

Khaled Omar, a police colonel in the town, told the AFP news agency that the attack took place outside a house used as a court annexe to interrogate suspects in “terrorist attacks”.

Elsewhere, at least seven civilians were killed and 20 injured by two bombs hidden in piles of rubbish in a market in Baghdad’s Sadr city.

The bombing in Tal Afar followed a twin car bomb attack in the city of Mosul on Wednesday that killed at least 14 people and wounded 33 others.

Tal Afar, in Nineveh province close to the Syrian border, was the scene of one of the deadliest attacks in Iraq, killing at least 152 people in March 27, 2007.

The province is said to be a stronghold of al-Qaeda and other armed groups as well as the scene of growing tensions between the regions Arab, Kurd and Turkmen communities.

Hussein Atrish, the head of Tal Afar’s town council, said armed groups were trying to roll back efforts to bridge divisions between the communities.

“The biggest problem is that there are people who are not comfortable with this reconciliation … terrorists do not welcome this,” he said.

US combat troops pulled out of the centres of all cities and major towns across Iraq on June 30 as part of a plan to withdraw all US forces by 2012.

The withdrawal, mostly to bases at the edges of cities, shifts the burden for keeping Iraqi streets safe mainly on the local police and soldiers, whose ranks have been rebuilt after they were disbanded following the invasion of Iraq by US-led forces.

The four weeks leading up to the US withdrawal witnessed the highest death toll in 11 months, according to official figures.

A total of 437 people, including 372 civilians, were killed in June, according to the figures compiled by government ministries. – Al Jazeera