Taliban militants on Thursday pledged to take revenge for the US airstrike that destroyed a Pakistani army post near the Afghan border and killed 11 paramilitary troops this week, reported dpa.
"We have the right to defend our country. Any aggression by NATO forces inside Pakistan will be responded with full force," said Dr Asad, a spokesman for Tehrik-e-Taliban Pakistan, reported dpa.
The Pakistani border post came under fire in the remote tribal district of Mohmand Agency when US planes targeted Taliban fighters fleeing after an attack on Afghan and NATO forces late Tuesday.
Eleven troops from paramilitary Frontier Corps were killed and 13 were injured. According to the Taliban's claim, eight of their comrades also died in the airstrike that was strongly condemned by Pakistani officials.
Denying that Taliban fighters had attacked NATO forces from Pakistani soil, Islamabad condemned the US bombardment as a "cowardly attack," using the harshest tones since the country joined the US in its fight against Islamic extremists after the 2001 attacks in New York and Washington.
The government also summoned US Ambassador Anne Patterson to the foreign office to receive Pakistan's formal protest. "The need for a high level investigation into the circumstances of this incident was also underscored," a statement from the foreign ministry said.
Prime Minister Yousaf Raza Gilani said such attacks were totally "unacceptable" for Pakistan, a key US ally in the fight against extremists.
The US Defence Department called the airstrike near the border a legitimate act of self-defence.
"US forces, operating on the border of Pakistan in Afghanistan territory, came under attack from hostile forces and, in self-defence they called in an airstrike, which took out those forces that were attacking them," Pentagon spokesman Geoff Morrell said.
Although the exact circumstances of the incident remained unclear, local English-language newspaper The News reported the tensions started when around 80 US and Afghan soldiers tried to set up a border post in disputed mountainous Sheikh Baba area, over which both Pakistan and Afghanistan lay claim.
NATO forces believe Taliban militants use the strategically important area to launch cross border attacks on international forces in Afghanistan. When Pakistani forces tried to stop US and Afghan forces, an exchange of fire broke out, the report said.
Taliban took benefit of the situation and ambushed US and Afghan forces from both sides of the border, prompting the airstrikes.
Analysts said the bombing would further complicate US-Pakistan relations already strained since March, when the new Pakistani government opened peace talks with local Taliban.
The sides are negotiating for a peace deal under which Pakistan would pull out troops from tribal areas in return for an end to strikes at government forces, a prospect that has raised concerns in Washington.
Owais Ghani, governor of the North-West Frontier Province that borders Afghanistan, warned that Pakistan would be left "with no choice but to review (its) policy on war on terror if such attacks continue in future."
Meanwhile, local media reported Thursday that US planes bombed some areas in tribal areas for the second straight night Wednesday.
No casualties were reported in the bombing on Zyob Mountain in South Waziristan by two US planes.
The continuing strikes and violation of Pakistani airspace have drawn heavy criticism in the South Asian nuclear-armed country.
Hundreds of people from Mosakhel and Safi tribes in Mohmand Agency said they would raise an army of local fighters to defend the border.
"Our forces did not give a timely response to NATO attack on our soil, so we are compelled to organize an army of our own fighters to defend our borders," Geo news channel quoted a tribal elder as saying.
Locals in Mohmand district fear that Taliban would benefit from heightened anti-American sentiments in volatile tribal region.
"The NATO attack will further strengthened militancy as more and more people will now join Taliban folds. The attack helped militants to get people sympathies. It will further deteriorate the situation," Ghafar Khan, a resident of Ghalanai area of the district told Deutsche Presse-Agentur dpa.