By Qasim Nauman and Michael Georgy
ISLAMABAD (Reuters) - Pakistan's commanders in the wild Afghan border region can return fire if under attack without waiting for permission, the army chief said on Friday, a policy change that could stoke tensions after Saturday's NATO strike killed 24 Pakistani troops.
Exactly what happened in the attack is unclear. Two U.S. officials told Reuters early indications were that Pakistani officials had cleared the NATO air strike, unaware they had troops in the area. A Pakistani official denied this.
The attack sparked fury in Pakistan and further complicated U.S.-led efforts to ease a crisis in relations with Islamabad, still seething at a secret U.S. raid in May which killed al Qaeda leader Osama bin Laden, and stabilize the region before foreign combat troops leave Afghanistan in 2014.
"I do not want there to be any doubt in the minds of any commander at any level about the rules of engagement," Chief of Army Staff General Ashfaq Kayani said in a communique on Friday.
"In case of any attack, you have complete liberty to respond forcefully using all available resources. You do not need any permission for this."
A military source explained that this amounted to a change in the rules for Pakistani forces guarding the Western border against militant movements to and from Afghanistan.
"In the past, we were only guarding ourselves or reacting against militants," said the source, who requested anonymity because he is not authorized to speak to the media.
"We have given our posts some more space to respond. If they are under attack, they should not wait for orders from above on whether to return fire or not."
The increase in autonomy for local commanders is likely to raise tensions in the unruly and mountainous border region, which is porous and poorly marked. Militants and tribespeople alike move back and forth daily.
"There are certain inherent risks in the delegation of authority," said defense analyst and retired general Talat Masood. "There could be unintended consequences."
Exactly what happened at the Pakistani posts along an unruly and poorly defined border is still unclear.
Pakistan said the attack was unprovoked, with officials calling it an act of blatant aggression -- an accusation the top U.S. military officer flatly rejected in an interview with Reuters.
Two U.S. officials told Reuters on Friday that preliminary information from the ongoing investigation indicated Pakistani officials at a border coordination center had cleared the air strike, unaware they had troops in the area.
The U.S. officials, speaking on condition of anonymity to confirm details first reported by the Wall Street Journal, said an Afghan-led assault force that included U.S. commandos came under fire from an encampment along the border with Pakistan.
The commandos thought they were being fired on by militants but instead the fire came from Pakistani troops, they said.
A Pakistani military official categorically denied that account, saying the aircraft had already engaged when Pakistan was contacted.
"Wrong information about the area of operation was provided to Pakistani officials a few minutes before the strike," said the official, who was not authorized to speak to the media.
"Without getting clearance from the Pakistan side, the post had already been engaged by U.S. helicopters and fighter jets. Pakistan did not have any prior information about any operation in the area."
In a statement on its public relations website, Pakistan's military said that its response to the NATO strike was hampered by an inability to scramble its aircraft in time.
"The response could have been more effective if PAF (Pakistan Air Force) had also joined in. However, it was no fault of PAF," the statement said.
"The timely decision could not be taken due to breakdown of communication with the affected posts and, therefore, lack of clarity of situation, at various levels, including the Corps Headquarters and GHQ (General Headquarters)."
The Pentagon has declined to comment on details from the investigation until it is complete. Pentagon spokesman George Little acknowledged at a news conference that Pakistan had been asked but "elected to date not to participate" in the inquiry.
SOUND AND FURY
The United States and NATO have promised to investigate the incident, expressing regret on the deaths of Pakistani soldiers but the White House said it was premature to consider an apology when an investigation was still in its early stages.
Pakistan has shown its anger over the attack by blocking ground supply routes for NATO forces in Afghanistan, and pulling out of an international conference in Germany next week on Afghanistan, depriving the talks of a central player in peace efforts.
"I think it's safe to say that the incident has had a chilling effect on our relationship with the Pakistani military. No question about that," said another Pentagon spokesman, Captain John Kirby.
Western leaders have urged Islamabad to rethink its decision to boycott the conference, but the Pakistani parliament's national security committee Friday endorsed the decision.
Prime Minister Yusuf Raza Gilani said Pakistan's contributions to regional peace efforts have not been appreciated and his country has become a scapegoat for the "failings of international policies in Afghanistan."
"Clearly, there is a limit to our patience. Cooperation cannot be a one-way street," he said.
In Karachi, calls for defiance laced Friday prayer sermons.
"This (the NATO attack) is sheer cruelty and the rulers and the public must join hands to defend our country," an imam said at the Jamia Masjid mosque in an upscale neighborhood. "It's time we decide that we can spend our lives as poor people but not as slaves of Western powers.
"We should have complete faith in Allah, and if you follow Islam in the true spirit, we will have no problems surviving even if the U.S. and Western powers don't like us."
At a rally by the militant group Sipah-e-Sahaba, some 2,000 protesters held placards that read: "Jihad is the only response to the U.S." and "Friends of the U.S. are traitors to Islam."
In the city of Multan in southern Punjab, at a demonstration organized by an Islamist group, Abdul Ghaffar, 45, said: "We're going to teach America the kind of lesson that is going to make them forget about Vietnam."
(Additional reporting by Augustine Anthony in ISLAMABAD, Asim Tanveer in MULTAN, and Faisal Aziz and Imtiaz Shah in KARACHI and Phil Stewart in WASHINGTON; Writing by Chris Allbritton; Editing by Nick Macfie and Yoko Nishikawa)