Paramilitary forces patrol the streets of Peshawar, in northwest Pakistan on Saturday. – Photo by Reuters

KABUL: A spokesman for Nato-led troops in Afghanistan confirmed that Nato aircraft had been called in to support troops during an incident near the border with Pakistan, and its forces were “highly likely” responsible for deaths of Pakistani soldiers.

“Close air support was called in, in the development of the tactical situation, and it is what highly likely caused the Pakistan casualties,” said Brigadier General Carsten Jacobson, spokesman for the Nato-led International Security Assistance Force (ISAF).

“We are aware that there are Pakistani casualties, we don't know numbers, we don't know the magnitude of the incident,” he told Reuters.

Pakistani officials earlier said Nato helicopters had attacked a military checkpoint in northwest Pakistan and killed up to 28 troops.