MOSUL, Iraq: Five US troops were killed yesterday in the deadliest attack on American forces in Iraq for more than a year when a suicide truck bomber struck a police compound in the northern city of Mosul.

Two Iraqi police and an Iraqi soldier also perished in the blast, according to an Interior Ministry official. The US military considers Mosul, Iraq’s second largest city, to be the last urban bastion of Al-Qaeda in Iraq.

The attack comes amid a sudden upturn in bombings nationwide including a series of blasts in Baghdad that have dealt a blow to recent upbeat assessments by American commanders about Iraq’s fragile security.

A US military spokesman said that five soldiers were killed and two others wounded in the attack, adding that the patrol seemed to have been in the area by chance and was not deliberately targeted. “It appears to have been a target of opportunity as the ... convoy was passing the national police station, and not at the headquarters conducting training,” spokesman Maj. Derrick Cheng told AFP.

In other violence yesterday, three people were killed and seven wounded in two roadside bomb attacks, according to local security officials.

In one attack a woman was killed by an explosion that also wounded her husband and two children in Diyala province northeast of Baghdad. In a similar incident in the town of Yusifiyah south of Baghdad two civilians were killed and another four were wounded.

Security has improved dramatically since 2007 when Iraqi and US forces launched offensives against Al-Qaeda militants with the help of local US-financed and trained Sahwa “Awakening” militias.