KABUL, Afghanistan - Militants killed a U.S. soldier and a Pakistani yesterday after a meeting held in a Pakistani frontier town that sought to calm the worst clashes in years between Afghan and Pakistani troops policing a border crossed daily by Taliban and al-Qaeda insurgents.

The attack at Teri Mangal produced a rare American casualty inside Pakistan, which is a U.S. ally in the fight against terrorist groups but which has uneasy relations with Afghanistan over how to deal with insurgents.

Two American and four Pakistani soldiers were reported wounded, along with two civilians working for the NATO force in Afghanistan whose nationalities were not released.

An Afghan army brigade commander, Gen. Akrem, who attended the meeting, told the Associated Press that gunmen fired on the participants - including about 15 Americans - as they left a school building after the talks.

"From three directions the gunmen opened fire - from the window of a classroom, from a building outside the school, and from a hill," said Akrem, who like many Afghans uses only one name.

Afghan soldiers at the meeting had been disarmed, he said, but the U.S. soldiers had weapons and fired back. Pakistan does not allow U.S. troops to operate from its soil, but U.S. military officials in Afghanistan often come for meetings to discuss cooperation.

A U.S. military official in Washington confirmed the American casualties.

The official, who spoke on condition of anonymity because the incident was under investigation, said U.S. soldiers had gotten into a truck and were preparing to leave when a Pakistani militiaman walked up and opened fire. Return U.S. fire killed the gunman, the official said.

Pakistani Maj. Gen. Waheed Arshad blamed unidentified "miscreants" - a word often used by Pakistan's government to describe Islamic militants, who are active in the country's lawless border region.

The attack came the same day that a Taliban spokesman quoted supreme leader Mullah Omar as confirming the weekend killing of a top Taliban field commander. He said Omar also promised that the death of Mullah Dadullah would not undermine the Taliban insurgency.

Tensions have been running high between Afghanistan and Pakistan over controlling their 1,510-mile border and stemming the flow of Taliban and al-Qaeda extremists who stage attacks inside Afghanistan.

Afghan leaders accuse the Pakistani government of harboring and helping supporters of the Taliban regime, which was ousted by a U.S.-led offensive in late 2001. Pakistan denies supporting the Taliban.