Pakistan has banned NATO supply convoys from entering Afghanistan after fighting between NATO troops and militants led to the killing of three Pakistani soldiers, according to a military official from the NATO-led command in Afghanistan.
The troops were killed when three NATO helicopters crossed from Afghanistan into Pakistani airspace early Thursday and attacked a military outpost, Pakistani security officials said. Three troops were wounded as well, the officials said.
Supply convoys are all-important for the Afghan war effort, and officials from NATO's International Security Assistance Force (ISAF) were trying to persuade Pakistan to lift the ban. Coalition forces rely heavily on convoys from Pakistan to bring in supplies and gear.
ISAF said in a statement Thursday that its forces saw what they thought were insurgents trying to fire mortars at a coalition base in the Dand Patan District of Afghanistan's Paktiya province, near the Pakistani border.
An air weapons team targeted the suspected insurgents' firing position, located inside Afghanistan along the border area, and the aircraft entered Pakistani airspace briefly "as they engaged this initial target," the ISAF statement said.
After this strike, the "aircraft received what the crews assessed as effective small arms fire from individuals just across the border in Pakistan" and the ISAF aircraft, operating in self-defense, entered into Pakistani airspace and killed "several armed individuals."
Later, Pakistani military officials told ISAF that coalition aircraft struck its border forces.
"ISAF and Pakistani forces are reviewing the operational reporting to verify the exact location of the two engagements and the facts in this case, and we will work together to fully investigate this incident.
"Both sides have in mind that it is the insurgents, operating on the border between Pakistan and Afghanistan and violating the territorial sovereignty of both countries, that we are focused on fighting," the ISAF statement said.
ISAF issued "sincere condolences to the Pakistani military and the families of those who were killed or injured."
Three Pakistani security officials said the helicopters attacked the Mandato Kandaho outpost, which is 5 km (about 3 miles) inside Pakistani territory. The area targeted lies in the Kurram Agency, one of seven districts in the Pakistani tribal region.
The dead Pakistani soldiers are members of the Frontier Corps, according to the officials.
A senior administration official in the tribal region's Khyber Agency told CNN Thursday that Pakistan had temporarily stopped NATO supplies from entering Afghanistan in the area of Takhta Baig, which is located about 45 km (28 miles) from the border with Afghanistan.
The official asked to not be named because he was not authorized to talk to the media.