WASHINGTON (AP) - NATO and Pakistani forces may have attacked one another in a tragic case of mistaken identity - each thinking the other side was Taliban, according to the first battlefield accounts after the worst incident of fratricide since the Afghan war began.
According to the U.S. military records described to The Associated Press, a joint U.S. and Afghan patrol requested backup after being hit by mortar and small arms fire by Taliban militants. Before responding, the joint U.S.-Afghan patrol first checked with the Pakistani army, which reported it had no troops in the area, the military account said.
A Pakistani army timeline presents a dueling narrative, of Pakistani frontier scouts spotting what they thought was suspicious activity, and opening fire, not knowing a friendly patrol was carrying out an operation in their area.
U.S. officials are also investigating the possibility that the Taliban may have lured a joint U.S-Afghan patrol into attacking friendly Pakistani border posts, according to preliminary U.S. military reports.
The NATO air assault over the weekend killed 24 Pakistani soldiers and injured more than a dozen others. The incident has sent the perpetually difficult U.S.-Pakistan relationship into a tailspin.
Both militaries say the engagement lasted roughly two hours. What's unclear is why the U.S. aerial bombardment of Pakistani border posts continued, long after Pakistani officials say they reported to NATO that their forces were under fire.
Officials described the records on condition of anonymity to discuss classified matters.
On Tuesday, Pakistani Gen. Ashfaq Nadeem called the incident a "deliberate act of aggression" and said it was "next to impossible that NATO" did not know it was attacking Pakistani forces.
Pentagon press secretary George Little declined to respond directly.
"No one at this point has the complete narrative on what happened and I think it's important that we wait for the investigation to occur," Little said.
Gen. James Mattis, head of U.S. Central Command, announced Monday he has appointed Brig. Gen. Stephen Clark, an Air Force special operations officer, to lead the probe of the incident, and said he must include input from the NATO-led forces in Afghanistan, as well as representatives from the Afghan and Pakistani governments.
Nadeem said the Pakistani army had little faith that any investigation will get to the bottom of the incident and may not cooperate with it. He said other joint inquiries into at least two other similar - if less deadly - incidents over the last three years had "come to nothing."
Nadeem made the remarks during a briefing with Pakistani journalists and defense analysts in army headquarters. Foreign media were not invited, but two attendees relayed Nadeem's comments to The Associated Press.
The U.S.-Afghan patrol thought it was under fire from Taliban militants just after midnight Saturday morning, the account said. The U.S. account said the patrol checked with the Pakistani military at the outset, and was assured there were no friendly troops in the area. The Pakistani military disputes that.
U.S. records show the aerial response included Apache attack helicopters and an AC-130 gunship, though it's unclear from the bare bones battlefield report when their bombardment started or ended.
Some two hours into the assault, the U.S. commander spotted what he thought was a militant encampment, with heavy weapons mounted on tripods, the U.S. account said. The joint patrol called for the airstrikes again at around 2:21 a.m. Pakistani time.
But the Pakistani account raises doubt as to whether Taliban were ever present.
In the Pakistani version of events, Pakistani border sentries heard suspicious activity about quarter past midnight - when the U.S.-Afghan patrol first reported contact with the Taliban. The Pakistani post fired flares to illuminate the area, and then followed that with small arms fire after spotting movement in the brush near their camp, according to a senior Pakistani official speaking on condition of anonymity to discuss the ongoing investigations.
Flares sound much like mortar fire - the type reported by the U.S.-Afghan patrol as their first contact with the Taliban.
The Pakistani base then took fire from U.S. aircraft, the official said, and reported they were under attack, which the Pakistani liaison then immediately reported at roughly 12:30a.m. to his U.S. counterparts where he was based at Forward Operating Base Joyce, on the Afghan side of the border. Yet the attacks continued, the official said, and the second Pakistani base opened fire on the aircraft to try to protect the first - so the aircraft engaged the second base as well, the official said.
NATO communicated at roughly 1:15am to the Pakistanis that NATO commanders realized they were attacking a Pakistani base, and had been ordered to stop, the official said. Yet the aerial bombardment continued, with a fresh salvo aimed at a Pakistani rescue force that rushed to the aid of the two posts.
While U.S. officials expressed regret and sympathy over the cross-border incident, they are not acknowledging blame, amid conflicting reports about who fired first.
The military fallout began almost immediately.
Pakistan has blocked vital supply routes for U.S.-led troops in Afghanistan and demanded Washington vacate a base used by American drones.
On the diplomatic front, Pakistan said Tuesday it will boycott an international conference on Afghanistan next week to protest the incident.
The decision to boycott the Bonn, Germany, conference was made during a Pakistani Cabinet meeting in the city of Lahore, said three officials who attended the meeting. They spoke on condition of anonymity because they were not authorized to talk to the media ahead of an official announcement.
The State Department also issued a new warning for U.S. citizens in Pakistan. It warned Americans to be on guard for possible retaliation.