The U.S. ambassador to Baghdad Christopher Hill narrowly escaped a roadside bomb explosion near his convoy in southern Iraq, the U.S. embassy said on Monday.

The attack took place on Sunday, when Hill was on a visit to Iraq's southern Dhi Qar province and its capital city of Nassriyah, some 375 km southeast of Baghdad, a U.S. embassy spokeswoman said.

"An explosive device detonated near a convoy carrying U.S. embassy personnel, including the ambassador," the spokeswoman said.

"No personnel were hurt and an investigation into the incident is underway," she said.

An Iraqi police source in the province said Hill's convoy was escorted by Iraqi police vehicles to the Talil airbase near Nassriyah, but the convoy split off the Iraqi security forces and took another route to the airbase where the attack took place.

Sporadic attacks have continued in Iraq despite a sharp drop in violence across the country in the past 18 months.

On June 30, U.S. troops pulled out from Iraqi cities and towns, according to agreement signed late last year between Baghdad and Washington, leaving the Iraqi security forces struggling to control security in the war-torn country on its own.

(Xinhua News Agency July 14, 2009)