KABUL, Afghanistan – U.S.-led coalition forces killed about 80 Taliban fighters during a six-hour battle outside a Taliban-controlled town in southern Afghanistan on Saturday, the latest in a series of increasingly bloody engagements in the region, officials said.

Also Saturday, a suicide bomber wearing an Afghan security uniform detonated his explosives at the entrance to a combined U.S.-Afghan base in the east of the country, killing four Afghan soldiers and a civilian, officials said.

The battle near Musa Qala in Helmand province – the world’s largest poppy-growing region – is at least the fifth major fight in the area since Sept. 1. The five battles have killed more than 250 Taliban fighters, a possible sign that U.S. or British forces could be trying to wrest the area back from Taliban militants.

The latest fight began when Taliban fighters attacked a combined U.S. coalition and Afghan patrol with rockets and gunfire, prompting the combined force to call in attack aircraft, which resulted in “almost seven dozen Taliban fighters killed,” the U.S.-led coalition said in a statement early yesterday.

The coalition said that four bombs were dropped on a trench line filled with Taliban fighters, resulting in most of the deaths.

Taliban militants overran Musa Qala in February, four months after British troops left the town following a contentious peace agreement that handed over security responsibilities to Afghan elders. Musa Qala has been in control of Taliban fighters ever since.

Situated in the north of Helmand, Musa Qala and the region around it have been the front line of the bloodiest fighting this year. It is also the heartland of Afghanistan’s illicit opium poppy farms.

Violence in Afghanistan this year has been the deadliest since the 2001 U.S.-led invasion. More than 5,200 people have died this year due to the insurgency, according to an Associated Press count based on figures from Afghan and Western officials.