Pakistan on Sunday buried 24 troops killed in a NATO cross-border air attack that has pushed a crisis in relations between the United States and an ally it needs to fight militancy towards rupture.
The incident was the latest perceived provocation by the United States, which infuriated Pakistan's powerful military with a unilateral U.S. special forces raid that killed Osama bin Laden in May.
U.S. and NATO officials are trying to defuse tensions but the soldiers' deaths are testing a bad marriage of convenience between Washington and Islamabad.
NATO helicopters and fighter jets based in Afghanistan attacked two Pakistan military outposts on Saturday, killing the soldiers in what Pakistan said was an unprovoked assault.
This was a tragic unintended incident, NATO Secretary-General Anders Fogh Rasmussen said in a statement, adding that he fully supported a NATO investigation that was under way. We will determine what happened, and draw the right lessons.
That is unlikely to cool tempers. Many Pakistanis believe their army is fighting a war against militants that only serves Western interests and hurts their country.
U.S. stabs Pakistan in the back, again, said a headline in the Daily Times, reflecting fury over the attack in Pakistan, a regional power seen as critical to U.S. efforts to stabilise neighbouring Afghanistan.
Television stations showed the coffins of the soldiers draped in green and white Pakistani flags in a prayer ceremony at the headquarters of the regional command in Peshawar attended by army chief General Ashfaq Kayani.
Foreign Minister Hina Rabbani Khar spoke with U.S. Secretary of State Hillary Clinton by telephone early on Sunday to convey the deep sense of rage felt across Pakistan.
This negates the progress made by the two countries on improving relations and forces Pakistan to revisit the terms of engagement, a Foreign Ministry statement quoted Khar as telling her U.S. counterpart.
Khar also informed Clinton that Pakistan wants the United States to vacate a drone aircraft base in the country.
Pakistan shut down NATO supply routes into Afghanistan -- used for sending in nearly half of the alliance's land shipments -- in retaliation for the worst such attack since Islamabad uneasily allied itself with Washington following the September 11, 2001, attacks on the United States.
About 500 members of Jamaat-e-Islami, Pakistan's most influential religious party, staged a protest in Mohmand tribal area, where the NATO attack took place.
Down with America and Jihad is The Only Answer to America, they yelled.
Pakistan is reviewing whether it will go ahead with plans to attend a major international conference in Bonn next month on the future of Afghanistan in light of the NATO attack.
Around 40 troops were stationed at the outposts at the time of the attack, military sources said.
They without any reasons attacked on our post and killed soldiers asleep, said a senior Pakistani officer.
The border is often poorly marked, and Afghan and Pakistani maps have differences of several kilometres in some places, military officials have said.
Pakistan responded with unusually blunt condemnations and said it reserved the right to retaliate.
Pakistan is a vital land route for nearly half of NATO supplies shipped overland to its troops in Afghanistan. Land shipments account for about two thirds of the alliance's cargo into Afghanistan.
A similar incident on Sept 30, 2010, which killed two Pakistani service personnel, led to the closure of one of NATO's supply routes through Pakistan for 10 days.
U.S. ties with Pakistan have suffered several big setbacks starting with the unilateral U.S. special forces raid in May that killed bin Laden in a Pakistani town where he had apparently been living for years.
Pakistan condemned the secret operation as a flagrant violation of its sovereignty, while suspicions arose in Washington that members of Pakistan's military intelligence had harboured the al Qaeda leader.
The military came under unprecedented criticism from both Pakistanis who said it failed to protect the country and American officials who said bin Laden's presence was proof the country was an unreliable ally in the war on militancy.
Pakistan's army, one of the world's largest, may see the NATO incursion from Afghanistan as a chance to reassert itself, especially since the deaths of the soldiers are likely to unite generals and politicians, whose ties are normally uneasy.
Pakistan's jailing of a CIA contractor, Raymond Davis, and U.S. accusations that Pakistan backed a militant attack on the U.S. embassy in Kabul have added to the tensions.
From Raymond Davis and his gun slinging in the streets of Lahore to the Osama bin Laden incident, and now to the firing on Pakistani soldiers on the volatile Pakistan-Afghan border, things hardly seem able to get any worse, said the Daily Times.
Islamabad depends on billions in U.S. aid and Washington believes Pakistan can help it bring about peace in Afghanistan ahead of a combat troop withdrawal at the end of 2014.
The fact is that such incursions of our sovereignty have become routine and we have become so dependent on the U.S. that we just have to grin and bear it, said an editorial in Pakistan's Express Tribune.
In Karachi port, dozens of truck drivers who should have been transporting supplies to Afghanistan were idle.
Taj Malli braves the threat of Taliban attacks to deliver supplies to Afghanistan so that he can support his children. But he thinks it is time to block the route permanently in protest.
Pakistan is more important than money. The government must stop all supplies to NATO so that they realise the importance of Pakistan, he said.
But some Pakistanis doubt their leaders have the resolve to challenge the United States.
This government is cowardly. It will do nothing, said Peshawar shopkeeper Sabir Khan. Similar attacks happened in the past, but what have they done?
(Additional reporting by Zeeshan Haider in Islamabad, Izaz Mohmand in Peshawar, Imtiaz Shah in Karachi and David Brunnstrom in Brussels; Writing by Michael Georgy; Editing by Nick Macfie)