A team of Pakistani security officials is in Kabul to probe the cross-border air strike by NATO helicopters that had killed three Pakistani soldiers leading to a standoff with the US-led forces in Afghanistan.
Pakistan protested against the attack, the fourth of its kind within a week, and shut the main border crossing used to transport supplies to NATO forces in Afghanistan.
The two-member team headed by Brig Usman Khattak, deputy inspector general of the Frontier Corps, and two liaison officers of the US are in Kabul since yesterday to investigate the cause of Thursday's cross-border attack in Kurram tribal region, Frontier Corps spokesman Maj Fazlur Rehman told PTI.
The Pakistani team will join an investigation by the International Security Assistance Force and US officials.
Khattak has visited the site of Thursday's attack and held talks with troops deployed in the area.
NATO claimed the attacks by its helicopters were carried out in self-defence but Pakistan reacted angrily, closing the Torkhum border crossing in Khyber tribal region.
The route remained closed for a fourth day today, leading to queues of over 100 trucks and tankers forming at the frontier.
Pakistani officials have said the border crossing will be opened for NATO supplies once public anger against the cross-border attacks subsides and the security of supply convoys can be assured.