One Iraqi police officer was killed and five Iraqi civilians were wounded Wednesday when a roadside bomb exploded near a U.S. convoy in Ramadi (search).

U.S. Marines arrested seven Iraqis, including six members of the Iraqi Civil Defense Force (search), for alleged involvement in the attack, military officials said. There were no U.S. causalities.

Associated Press Television News footage showed the smoldering wreckage of an SUV and a sedan, with ambulances speeding by.