KABUL, May 16: The Nato force in Afghanistan demanded on Wednesday that Pakistan investigate a border incident in which a US soldier was shot dead by a man said to be in a Pakistani paramilitary unit’s uniform.

About 1,000 Afghans meanwhile demonstrated outside the Pakistan embassy in Kabul chanting “Death to Pakistan” and accusing Islamabad of invading on Sunday, sparking clashes at the weekend that killed 13 Afghans.

Representatives of the Nato-led International Security Assistance Force (ISAF) were among a delegation that travelled just across the border into Pakistan on Monday to try to calm the tensions.

After the meeting “an individual reported to be wearing a Pakistan Frontier Corps uniform” fired into the group, a spokeswoman for ISAF said in a statement on Wednesday.

A US soldier was killed and three soldiers were wounded, as was a civilian.

“ISAF expects a full investigation of this incident by the Pakistani military,” Lieutenant Colonel Maria Carl said.

Pakistan has said one of its soldiers was also killed.

Afghan officials have said the man who opened fire was a Pakistani military officer but Pakistan has said the identity of the attacker was not known.

It is important that Pakistan “does actually go through a proper investigation into this incident so that we are clear about what happened,” the Nato force's spokesman in Afghanistan said.

“We will be expecting them to fulfil that part of their responsibility,”said the spokesman, Nicholas Lunt.

Pakistani military spokesman Major General Waheed Arshad said he was aware of the ISAF statement “but our investigations are still not concluded. We will respond to their statement once our own investigations are completed.”

Afghan officials also accuse the Pakistani side of starting the clashes on Sunday that continued into mid-Monday, saying they pushed up to four kilometres across the disputed border.

Thirteen Afghans were killed in the fighting, which included rocket fire.

Six of them were policemen and the rest civilians, including two schoolchildren, Afghan defence ministry spokesman General Mohammad Zahir Azimi said.—AFP