Pakistani officials, who were unaware that their soldiers were in the area, gave the green signal for NATO airstrikes that left 24 Pakistan Army soldiers dead, the Wall Street Journal reported Friday.

US officials said that Pakistani officials at a border coordination centre gave the NNATO forces the nod for the airstrikes, the Journal said.

The Nov 26 airstrikes on two Pakistan Army checkposts in Mohmand Agency killed two dozen soldiers, sparking outrage in Pakistan. Islamabad promptly barred the passage of NATO supplies through the country and decided to boycott the Bonn conference that would discuss the future course of action in Afghanistan.

US officials said that an Afghan-led assault force, including US commandos, was looking for Taliban guerrillas when they came under fire along the Afghan-Pakistan border.

The commandos thought that militants were firing at them, so they sought airstrikes against the encampment.

That request prompted contact with a joint border-control centre to determine whether Pakistani forces were in the area, a US official said, according to the Wall Street Journal.

The border-control centre is operated by US, Afghan and Pakistani representatives and they are supposed to share information to avoid conflicts, the WSJ said.

The official said the centre had not been told in advance about the commando operation.

The Pakistani representatives at the centre said there were no Pakistani military forces in the area, and so the Americans went ahead with the airstrikes.

'There were lots of mistakes made...There was not good situational awareness to who was where and who was doing what,' the official was quoted as saying.

US officials said the Pakistani positions were more like makeshift campsites than established military bases.

Also, since the Taliban and Pakistani Army use some of the same weaponry, it was difficult to tell who was firing at the assault force, the official added.