PESHAWAR: Two bombs minutes apart struck tribal police assigned to guard polio workers in northwest Pakistan, killing 11, police said.
Police official Nawabzada Khan said the first of the two bombs struck an escort vehicle in the Lashora village of Jamrud tribal region in Khyber Pakhtunkhwa province.
It wounded six officers, but caused no deaths.
Khan said minutes later, another roadside bomb struck a convoy of tribal police officers dispatched there to transport victims of the first attack, killing 11 officers and wounding six.
He said gunmen also opened fire on officers, triggering a shootout that was still going on.
A government administrator Nasir Khan said they had launched a massive hunt in effort to trace and arrest the attackers.
He confirmed 11 deaths and 12 injuries.
No one claimed responsibility for the two separate bombings, but anti-polio teams or their guards have been frequently targeted in Pakistan by militants, who say the campaigns are a tool for spying and claim the vaccine makes boys sterile.
Pakistan is one of the few remaining countries where polio persists. In most cases the disease is found in the northwest, where militants make it difficult to reach children for vaccination.
Also Saturday, a bomb targeting security forces in the southwestern province of Baluchistan killed three soldiers and wounded six others, the paramilitary Frontier Corps said.
In a statement, it said the soldiers were traveling through the border village of Washuk when a bomb hit their vehicle.
Washuk lies 400 km south of Quetta, the capital of Baluchistan province, where separatists have been fighting a bloody insurgency against the Pakistani government for decades.