KABUL, Afghanistan - NATO on Thursday said as many as 150 insurgents were killed in a battle in eastern Afghanistan after two large groups of fighters crossed the border from Pakistan.

The fighters were attacked with ground fire and airstrikes, NATO said. Gen. Murad Ali, the Afghan army regional deputy corps commander, said the insurgents had traveled into Paktika province with several trucks of ammunition.

A NATO statement said "initial battle damage estimates" indicated that as many as 150 fighters were killed. Ali said more than 50 fighters were killed late Wednesday and early Thursday. Mohammad Zahir Azimi, the spokesman for the Ministry of Defense, estimated the toll at 80.

It was not clear why there was such a disparity in the estimates. Independent confirmation of the death toll was not immediately possible on the remote battle site.

Azimi said one Pakistani fighter was wounded and captured. Rocket-propelled grenade launchers and machine guns were also recovered, he said.

Taliban militants last year launched a record number of attacks, and an estimated 4,000 people died in insurgency-related violence, the bloodiest year since the US-led coalition ousted the Taliban regime in late 2001.

The fight in the Bermel district of Paktika province is the first major engagement of 2007 and appeared to be the largest battle since a multi-day operation killed more than 500 suspected Taliban fighters in the Panjwayi district of Kandahar province in September.

NATO did not say how it estimated that 150 fighters were killed. In early December NATO said it had killed 70-80 fighters in Helmand province but days later said that only seven to eight were killed.

In the southern province of Helmand, meanwhile, NATO forces called in airstrikes on Taliban positions during a clash in the village of Gereshk on Wednesday, said Ghulam Nabi Mulahkhail, a local police chief.

Among those killed was a local Taliban group commander identified as Mullah Faqir Mohammad, the police official said. One Afghan soldier was wounded and evacuated to a NATO medical facility, the alliance said in a statement.

The troops recovered weapons and ammunition in the militant compound following the operation, the statement said.