U.S. and Iraqi soldiers battled insurgents for a second day in an Iraqi border town that is believed to be a key entry point for foreign fighters and weapons from Syria.
U.S. commanders said attackers fired small arms and rockets at coalition forces as they conducted house by house searches in Husaybah.
Officials said at least 17 insurgents have been killed and dozens arrested since the operation began Saturday. Three Marines also were reported injured.
Coalition airstrikes hit what were described as insurgent strongholds in the Euphrates river town.
Many residents fled the town ahead of the offensive, and coalition forces said about 450 people had been granted temporary refuge in the area.
U.S. officials say Husaybah is a key base for foreign fighters and arms from Syria. Syria has denied giving support to insurgents.