NATO Secretary General Anders Fogh Rasmussen on Sunday called "tragic and unintended" the deaths of 24 Pakistani soldiers. They were killed when NATO helicopters and fighter jets based in Afghanistan attacked two Pakistan military outposts on Saturday in what Pakistan said was an unprovoked assault.

The exact circumstances of the attack remain unclear.

In a statement, Rasmussen said he had written to Pakistani Prime Minister Yusuf Raza Gilani to make it clear that the deaths were "as unacceptable and deplorable as the deaths of Afghan and international personnel."

'Deep sense of rage'

Pakistan on Sunday held funerals for the dead soldiers at the headquarters of the regional command in Peshawar attended by army chief General Ashfaq Kayani.

Foreign Minister Hina Rabbani Khar spoke with US Secretary of State Hillary Clinton by telephone early on Sunday to convey "the deep sense of rage felt across Pakistan."

On Saturday, Pakistan accused NATO of violating its sovereignty in the border incident, which provoked Islamabad to shut down the Western alliance's overland supply routes to Afghanistan and demand that Washington vacate an air base.

The Pakistani military said in a statement that NATO helicopters "carried out unprovoked and indiscriminate firing" in the Mohmand tribal area. The incident killed 24 Pakistani troops and wounded 14 others, according to the governor of the northwestern Khyber Pakhtunkhwa province, Masood Kausar.

"This is an attack on Pakistan's sovereignty," said Prime Minister Yusuf Raza Gilani. "We will not let any harm come to Pakistan's sovereignty and solidarity."

In retaliation, Islamabad shut down the Torkham and Chaman border crossings, the main overland supply routes for the NATO-led International Security Assistance Force (ISAF) in Afghanistan. More than 30 percent of NATO's non-lethal supplies pass through the two border crossings.

The Pakistani government has given the US 15 days to vacate Shamsi Air Base, located in the southwestern Baluchistan province. Washington uses the base to service its drone aircraft, which are deployed to target al Qaeda operatives and members of militant networks.

"A strong protest has been launched with NATO/ISAF in which it has been demanded that strong and urgent action be taken against those responsible for this aggression," said General Ashfaq Pervez Kayani, Pakistan's chief of army staff.

Troubled relations

The strike, the deadliest of its kind since the US invaded Afghanistan after the September 11 attacks, threatens to damage already strained Pakistani-US relations. Islamabad regularly complains that Washington's campaign of drone strikes targeting Islamic militants violates its national sovereignty.

Washington, in turn, accuses the Pakistani military and intelligence establishment of supporting or turning a blind eye to militant safe-havens in the tribal regions along the Afghan frontier.

In congressional testimony last September, former US joint chiefs chairman Admiral Mike Mullen flatly stated that Pakistani intelligence had supported an attack by the Haqqani network on the US embassy in Kabul.

Relations between the estranged allies had already hit a historic low point in the aftermath of a unilateral US raid that killed al Qaeda chief Osama bin Laden, who had been hiding in a compound located in the town of Abbottabad, home to Pakistan's premier military academy.

Author: Spencer Kimball, Joanna Impey (AP, AFP, dpa, Reuters)
Editor: Sonia Phalnikar