Nato helicopters from Afghanistan wounded two Pakistani soldiers in a cross-border attack Tuesday, officials said, triggering a "strong protest" from Islamabad as tensions with the US simmered after Osama bin Laden's death.
The two choppers opened fire on an army checkpoint in Wacha Bibi in North Waziristan tribal district, after they were shot at, a Western military official in Kabul said.
Washington considers the tribal belt a hotbed of al Qaeda.
"Pakistan's army has lodged a strong protest and demanded a flag meeting" with Nato officials in Afghanistan, a statement issued in Islamabad said.
5 bombers killed
Security forces shot dead five suspected al Qaeda-linked militants who had tried to carry out a suicide bombing in Quetta on Tuesday.
The would-be bombers included three women and were believed to be foreigners.
"It looks they were either Uzbek or Chechens," a senior security official said.
"They had grenades and bombs strapped to their bodies."