BAGHDAD, Iraq —  A U.S. Army supply unit whose members refused a dangerous fuel delivery mission last month has now fitted its vehicles with armor to protect against attack, the military said Saturday.

Eighteen soldiers from the 343rd Quartermaster Company (search), a Reserve unit based in Rock Hill, S.C., refused to drive a fuel convoy last month from Tallil air base near Nasiriyah to Taji north of Baghdad, insisting their vehicles were not properly outfitted and the fuel was contaminated.

The mission later was carried out by other troops in the unit, which has at least 120 soldiers, the military said. Their commander was later relieved, but senior officers denied the fuel was contaminated.

In a statement Saturday, the military said the unit was still carrying out inspection, maintenance and training, and had resumed limited operations.

"Specifically, they are supporting convoy missions by providing gun truck escorts and crews as well as serving as vehicle commanders and crew members in the vehicles of sister units," the statement said. "The 343rd expects to resume fuel delivery missions, with their own vehicles, in the near future."

The statement said all the unit's M931 Tractors (search) and 5-ton gun trucks have been fitted with fabricated armor. In addition, all Humvees have factory add-on armor, the statement said.

The command declined comment on possible punishment for soldiers who refused the supply mission because the investigation was ongoing.