A coalition statement said the fighting came after 40 insurgents attacked a joint Afghan-coalition patrol on September 16.
The coalition said it used small-arms fire and air strikes against the militants in Garmser district.
Helmand Province has seen some of Afghanistan's bloodiest fighting in the past two years.
Afghanistan's Opium Problem
OPIUM FARMING ON THE RISE Despite a nationwide program by the Afghan government to eradicate opium-poppy fields and offer farmers alternative crops, international experts say that the 2006 opium crop was as much as 50 percent larger than the previous year's record crop. Afghanistan also accounted for practically all of the world's illegal opium production.(more)