Baghdad - A US soldier was killed in a bomb blast that targeted a convoy north of Baghdad on Sunday, a US military statement said, taking the number of American soldiers killed in recent days to six.

    "One US coalition soldier died of wounds sustained when an improvised explosive device detonated in Salaheddin province," the statement said. "The soldier was in a convoy when the vehicle has hit."

    The latest deaths bring the total number of US casualties since the March 2003 invasion to topple Saddam Hussein to 4,272, according to an AFP count based on the independent website icasualties.org.

    Five US troops were killed on Friday 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 Friday's blast, according to an interior ministry official.

    The deaths come 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.

    At least 71 people have been killed and more than 300 injured in violence in the past week.

    Lieutenant General Lloyd Austin, the US army's second-highest ranking officer in Iraq, said in Baghdad on April 1 that recent "high-profile" attacks were not a signal that the security situation was worsening.

    US soldiers are preparing to withdraw from Iraqi cities and major towns by June 30 and from the entire country by the end of 2011.