US Marines who took back a key town in southern Afghanistan from Taliban militants in an operation earlier this year turned over responsibility for the area to British and Afghan forces on Monday.

The 24th Marine Expeditionary Unit is pulling out of Garmser in the southern province of Helmand and beginning to head back to Camp Lejeune in North Carolina.

The unit launched the operation in the Taliban-held area in late April and killed more than 400 militants during 35 days of fighting, according to Helmand's governor. The Marines suffered three hostile deaths, two from a roadside bomb and one from gunfire.

Col. Peter Petronzio, commander of the unit, said his forces had accomplished theirgoal.

"We are not going to solve all the problems with 2,500 Marines for seven or eight months, but what we can do is eat this elephant one bite at time, and we took a big bite and we did some great things in Garmser, and for the people there it will be a lasting, lasting success.” Petronziosaid.

The unit's original mission was to clear a road through the Taliban-occupied area so troops could travel south. But the Marines were met with such fierce Taliban resistance that commanders decided to keep them in Garmser for their entire deployment.

US commanders said they believed the militants defended Garmser with such intensity because it is a key transportation route for fighters, weapons and

drugs. Garmser was filled with opium poppies this spring when the Marines arrived, but the forces did not touch the illegal crops.

The British military is responsible for Helmand province, but its 7,500 soldiers, along with 2,500 Canadian troops in neighbouring Kandahar, haven't had enough manpower to tame Afghanistan's south.

The Marines' mission in the south could be a precursor to future American operations in Kandahar and Helmand provinces, two of the country's most violent regions.

The Garmser operation allowed the Afghan government to move back into Garmser for the first time in years.The relative peace allowed a civic centre and a medical clinic to open.