In the deadliest attack, four Iraqi soldiers were killed and three wounded in an ambush of a convoy carrying a regiment commander in the town of al-Nibaie, 45 kilometres (30 miles) north of the capital.

The three-vehicle convoy was initially hit by multiple roadside bombs, and subsequently came under attack by gunmen, an Iraqi army captain said.

There were no casualties from the blasts, but four soldiers were killed and three wounded in the shooting, the captain and an interior ministry official said. Both spoke on condition of anonymity.

Among the dead was the regiment commander, an Iraqi army colonel.

Also on Tuesday, gunmen killed two Iraqi army soldiers, including a lieutenant, in a drive-by shooting in north Baghdad.

The gunmen, who were driving in two cars, opened fire using silenced pistols on a military pick-up truck in Waziriyah, killing the two, an interior ministry official and a medical source said.

The latest deaths took to 265 the number of people killed in nationwide attacks so far in August, according to an AFP tally based on reports from security and medical officials.

Violence has significantly decreased in Iraq compared to the brutal years of 2006 and 2007, but attacks are still common.