Nato officials in Afghanistan say that air and artillery strikes have killed a further 92 Taleban fighters in Kandahar province on Sunday.
Correspondents say the fighting is the heaviest since Nato's formation
The reported casualties are in addition to 94 Taleban fighters which Nato says were killed earlier over the week-end in the Operation Medusa offensive.
There has been no independent verification of the Nato figures.
The reports come five years after the 9/11 attacks in the US that resulted in the US-led invasion of Afghanistan.
The latest violence coincides with the death on Sunday of the governor of eastern Afghanistan's Paktia province by a suicide bomber.
Abdul Hakim Taniwal was the highest-ranking official to die in the insurgency.
The academic - who campaigned against Afghan gun culture - was killed outside his office. The Taleban said it was responsible.
The BBC's Damian Grammaticus has visited the frontline of the latest clashes and says that Nato forces are engaged in the biggest battle sine the US invasion of Afghanistan.
Our correspondent says that five years after the World Trade Centre attack, the Taleban have had time to regroup in the huge Panwaj dessert in the south.
It is an area with perfect defensive positions, criss-crossed by drainage ditches and low mud walls.
Nato says the Taleban sustained its most recent casualties when insurgents staged a counterattack in Kandahar province on Sunday.
Mr Taniwal was an academic with Australian citizenship
It says that the insurgents were killed in Zari and Panjwai districts of the southern province of Kandahar.
"Further analysis of yesterday's battle damage assessment reports that 92 insurgents were killed. This figure is separate from the 94 insurgents killed in the other incident earlier Sunday," a Nato spokesman said.
But there has been no independent confirmation of the number of Taleban casualties as a result Operation Medusa, which began on 2 September and which Nato says has now killed over 500 insurgents.
The Taleban have disputed the high figures and said the alliance should display bodies as proof.