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.