| MIRANSHAH, Pakistan/KABUL
MIRANSHAH, Pakistan/KABUL NATO helicopters from Afghanistan intruded into northwest Pakistan Tuesday, wounding two soldiers, officials said, prompting a protest from the military already seething over the secret U.S. operation to kill Osama bin Laden.
The Pakistani Army said it had lodged a "strong protest" and sought a flag meeting with NATO commanders over the incursion in Pakistan's North Waziristan near the Afghan border which has been repeatedly targeted by U.S. drone aircraft as a hub of al Qaeda linked militants.
A Western military official in Kabul, however, said two NATO helicopters supporting a base in eastern Afghanistan had returned fire after being attacked from Pakistan, but declined to say whether they had crossed into Pakistani airspace.
A senior Pakistani security official said NATO has lodged its own complaint with Pakistan, accusing its forces of "unprovoked firing." Western military officials in Kabul had no immediate comment about the possible complaint.
The incident is certain to weigh on relations between the U.S. and Pakistan have been pushed almost to the breaking point after the May 2 raid on Abbottabad that killed bin Laden, with Pakistan's parliament condemning the operation as a violation of the nation's sovereignty.
It also came hours after Pakistani Prime Minister Yusuf Raza Gilani landed in Beijing for a visit that underlines Islamabad's close and productive ties with another major power.
A Western military official, who asked to remain anonymous, said NATO helicopters had fired at targets inside Pakistan, but only after they were attacked from across the border.
Pakistan's frontier has been described as a global hub for militants, and Tuesday, police said they had killed five suspected al Qaeda militants who had tried to carry out a suicide bombing at a paramilitary checkpoint in the southwestern city of Quetta.
The would-be bombers included three women and were believed to be foreigners, police said.
Quetta is believed to be a base for the Afghan Taliban leadership and if the attack had been carried out, it would have been the second targeting Pakistan's military since bin Laden was killed and the Pakistan Taliban vowed to avenge his death.
BREACH OF AIRSPACE?
A local government official said two NATO helicopters crossed into North Waziristan and remained for about 10 minutes in the area, known to be a hub for al Qaeda-linked fighters including the Haqqani network that is leading the insurgency in eastern Afghanistan.
The helicopters retreated after Pakistani border forces opened fire in the Datta Khel area about 40 km (24 miles) west of the main town of Miranshah, a security official said.
"A shell struck a mountain nearby and two of our soldiers were wounded by the rubble," the official said.
The Western military official said the helicopters came under fire first.
"Our initial reports indicate that two ISAF helicopters were in the area in support of FOB (forward operating base) Tillman, as the FOB had been receiving intermittent direct and indirect fire from across the Pakistani border," he said.
"Upon arrival the helicopter received fire from across the border but did not immediately return fire. Upon receiving fire from across the border a second time, the helicopter returned fire," he added.
The official said the NATO-led coalition had received reports two Pakistani troops had been wounded. He declined further comment, including on whether the helicopters had entered Pakistan airspace.
Pakistan has in the past reacted angrily to incursions by NATO aircraft, even though its air space is routinely breached by unmanned drone aircraft.
A previous incursion on September 30, 2010, killed two Pakistani troops and wounded four more when NATO helicopters crossed the border while pursing insurgents. Pakistan retaliated by shutting down the supply route for NATO troops in Afghanistan.
TENSE US TIES
In Pakistan this week, Senator John Kerry who is close to U.S. President Barack Obama, tried to smooth relations in the wake of the bin Laden raid, but also warned that Washington would not tolerate any of Pakistan's alleged double-dealings with militant groups.
Bin Laden's discovery in the comfortable garrison town of Abbottabad, only 50 km (30 miles) from the capital, has deeply embarrassed the military and spy agency, reviving suspicion that Pakistan knew where he was and has been playing a double game.
Pakistan has rejected that as absurd, but the United States has stepped up drone attacks against suspected militants since bin Laden's killing despite Islamabad's objections.
Several Pakistani helicopters took off from Waziristan's main town of Miranshah toward the site of Tuesday's reported incursion, a Pakistani officials said.
"After the May 2 incident, there is a high alert on the border," a security official said. "Forces have been ordered to respond quickly if there is any attempt of intrusion."
Separately, a Pakistani helicopter gunship destroyed a wireless communication installation established by militants in mountains near Miranshah town in an strike Tuesday, an intelligence official in the region said.
North Waziristan is the base of the Haqqani network blamed for the insurgency in eastern Afghanistan. U.S.-led drone aircraft have targeted the area over the past year and Washington has repeatedly urged the Pakistan military to launch a ground operation.
Many militants, including foreign fighters loyal to al Qaeda, are based in Datta Khel. It is a stronghold of fighters loyal to Hafiz Gul Bahadur and has been a frequent target of U.S. drone strikes.
Monday, unmanned U.S. drone aircraft fired missiles in Datta Khel killing 12 militants, Pakistani officials said.
An intelligence official said that one of the dead militants, an Arab, was the son of an al Qaeda operative identified as Abu Kashif. There was no way to verify the death toll. Militants often dispute official accounts of drone attacks.
(Writing by Chris Allbritton; Additional reporting by Zeeshan Haider and Kamran Haider in Islamabad and Emma Graham-Harrison in Kabul; Editing by Sanjeev Miglani)