Up to 22 people were killed and many more wounded when two suicide truck bombs exploded in a town in northern Iraq today, targeting a police chief and a tribal leader who had joined forces with the US military against al-Qaeda.

The attacks raised fears of further bloodshed during the holy month of Ramadan – a time that has been marred in the past by headline-grabbing “spectacular” bombings, though US commanders have noted that violence this year is lower.

Challenging the new trend, the two bombers struck within minutes of each other in the Sunni Arab town of Baiji, 110 miles (175km) north of Baghdad. The first pick-up truck targeted Colonel Saad Nifous, the town’s police chief, who was wounded in the blast.

"Three houses were completely demolished,” said Lieutenant-Colonel Fadhil Mahmoud, of the provincial Salahuddin police. “Eight people were killed and 16 wounded and they are still searching for other bodies under the rubble.”

The second truck bomber attacked the house of Thamir Attallah, the military chief of the Sunni Arab “Awakening” council in Baiji.

Earlier, a police source in Baiji had said the target of that bombing was Hamad al-Jubouri, the leader of the Salahuddin Awakening, as he attended a mosque. It was not immediately clear if he was among the victims.

Casualty figures varied, with some sources putting the death toll at 22 and others at 18. About 50 people were injured in the blasts.

Awakening councils, such as the one led by Mr Jubouri, are based on a model first adopted this year in Anbar province, west of Baghdad. Under the grassroots uprising, Sunni Arab sheikhs, sponsored by the US military, are turning against al-Qaeda and organising young men to don uniforms and protect their neighbourhoods.

Attacks in Anbar have plummeted as a result, much to the delight of President Bush, who points to the province as proof that his surge of 30,000 extra troops in Iraq is working.

Choosing to side with the American forces is a risky business, however. Last month a roadside bomb killed Sheikh Abdul Sittar Bezea al-Rishawi, who led the Anbar Awakening in western Iraq.

Sheikh Sittar, 36, had been lauded by General David Petraeus, the top US commander in Iraq, during testimony to Congress, for helping to transform a region that was once the heart of the anti-American insurgency into one of the safest provinces in Iraq.

Responding to the latest attacks, the spokesman for US troops in northern Iraq said: “This is yet another failed attempt to break the will of the Iraqi people.”

Further denting the relative calm of this year’s Ramadan, a parked car bomb struck a commercial area of Baghdad today, killing at least eight and wounding 25 people, including four traffic policemen.

Another two people died and 16 were injured when a second car bomb exploded in the capital’s predominantly Shia neighbourhood of Shaab.

Al-Qaeda in Iraq had given warning that it would increase attacks during Ramadan, which is drawing to a close. The Sunni Islamist group has also threatened to target Iraqis who have joined US forces in fighting local al-Qaeda members.

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