The men were seen gathering on the Pakistan side of the border and crossing into the eastern province of Paktika in two large groups, Nato's International Security Assistance Force said. They were "monitored, tracked and subsequently engaged in Afghanistan, through the co-ordinated use of both air and ground fire in a series of engagements," it said in a statement.
Afghan Defence Ministry spokesman Mohammad Zahir Azimi told AFP that Nato bombed the insurgents just two kilometres (1.2 miles) from the Pakistan border in Barmal district. Afghan ground forces also attacked, he said. "Initial battle damage estimates indicate as many as 150 insurgents were killed," Isaf's statement said.
The Afghan Defence Ministry put the toll at around 80. One man was arrested and a large number of guns and ammunition confiscated, a ministry statement said. Parts of enemy bodies littered the scene of the attack and a trail of blood could be seen going towards the border, it said, adding there was no injury to Afghan forces.
Isaf said Pakistani military liaison officers were kept fully informed throughout the operation. Purported Taliban spokesman Mohammad Hanif however, denied that the movement's fighters were involved and claimed the dead were all civilians.