Nato forces in southern Afghanistan say they have killed about 70 Taleban fighters following an ambush.
Troops fought a four-hour battle after a large-scale insurgent attack near the town of Musa Qala in Helmand Province, the alliance says.
British troops recently brokered a truce with rebels to allow local forces in Musa Qala to police the area.
The attack may fuel suspicions the Taleban use Musa Qala as a safe haven, a BBC correspondent in Kabul says.
A Danish patrol serving alongside British troops came under fire outside Musa Qala and called in air support, a Nato spokesman said.
Between 70 and 80 suspected Taleban died in the battle and no Nato troops were killed, he added.
There was no independent confirmation of the death toll.
The attack happened outside the area of Musa Qala covered by the deal struck in October between British forces, Taleban fighters and local elders.
The Musa Qala attack was just one incident in a violent weekend in southern Afghanistan.
In the city of Kandahar, a suicide car bomb exploded near a British convoy.
The Kandahar car bomb exploded near a British convoy.
Three Afghans were killed and three British soldiers injured.
There were reports of further civilian injuries in clashes following the bombing.
Alliance officials also confirmed that a Nato-chartered transport helicopter carrying eight crew crashed in the north of Kandahar province on Saturday.
There was no sign that anyone had survived.
The Taleban said they shot down the helicopter, but this could not be confirmed.
Nato-led forces fighting in southern Afghanistan are facing the fiercest resistance from militants since the toppling of the Taleban regime five years ago.