KABUL, Afghanistan — NATO Forces in Afghanistan claimed yesterday to have thwarted a major Taliban border incursion from Pakistan by killing up to 150 insurgents in a nighttime operation.

As part of what was thought to be a precursor to a Taliban spring offensive, NATO officials said two columns totaling some 200 insurgents crossed into the Afghan border province of Paktika on Wednesday night.

Pakistani forces were informed of the movement of Taliban fighters, and the Pakistani military claimed that it bombed and destroyed trucks used by the Taliban on its side of the border.

If so, it was the first military action by the Pakistani military since the government signed a peace deal with militants last year. American military commanders say border incursions have increased threefold since the deal.

The fighting took place as the British commander of NATO forces in Afghanistan, General David Richards, visited the Pakistani capital to coordinate military strategy between NATO, Afghan, and Pakistani forces.

Pakistan has come under criticism from NATO commanders for not doing enough to stem Taliban “infiltration.” Pakistan denies the charge.

The group of Taliban fighters had assembled in the mountainous terrain of North Waziristan and were seen by American reconnaissance units as they dismounted from trucks before filing over the border at two points.

As they entered Bermal district on the Afghan side of the border at 7 p.m., American Apache assault helicopters firing air-to-surface missiles and machine-gun rounds attacked them.

Attack aircraft then dropped a mixture of 500 to 1,000lb bombs on the two groups. The coordinated air and ground strikes just 1.2 miles inside Afghan territory were reported to have all but annihilated the Taliban force. The Afghan army reported that the Taliban dead, their weapons and ammunition littered the site of the fighting with blood trails apparently showing where wounded men were carried back toward the Pakistan border.

A NATO spokesman said there were no reports of civilian casualties. A purported spokesman for the Taliban, Mohammad Hanif, denied that any Taliban were involved in the fighting and claimed all those killed were civilians.

The fighting, although not continuous, lasted for nine hours as Apache aircraft tracked the disintegrating columns as fighters fled into the mountainous terrain.

“We think that we killed at least 130 fighters from what we have been able to ascertain through visual recognition,” a spokesman for American forces in Kabul, Lieutenant Colonel Paul Fitzpatrick, said. “We are very confident we did heavy damage on these two columns,” he added.

Colonel Fitzpatrick said there were several American bases and outposts within walking distance of the Taliban fighters.

“It was a bold attack which they did not have the opportunity to pull off,” he said.

Pressure has been mounting on Pakistan to do more to tackle the cross-border movement of insurgents. As Pakistan claimed to have destroyed the lorries used by the Taliban on its side of the border, the American assistant secretary of state, Richard Boucher, continued his policy of gentle pressure on Islamabad’s military regime.

“Pakistan is a very important ally in the fight against terrorism,” he said. “There are successes on both sides of the border, there are strong commitments on both sides of the border to deal with extremism. … There are also challenges on both sides of the border.

“It is clear to me none of us will be safe unless we deal with both sides of the border. … We are all in this together.”

American and NATO officials maintain that President Musharraf of Pakistan cannot be pushed too hard to crack down on Islamic radicals for fear of provoking a violent backlash. General Richards said: “Today in Afghanistan the number of incidents have declined dramatically from the highs of the last summer. The reduction is to a degree the result of Pakistan army activity and we are the beneficiaries of that.”

But he added that the 1,553 miles of rugged frontier still posed a big challenge.

The bloodshed was the result of violence of unprecedented severity for Afghanistan’s traditionally quiet winter months.