A member of a polio vaccination team and two policemen in charge of their protection were killed on Tuesday by gunmen in northwestern Pakistan, an area where such attacks are frequent, we learned from police sources.

The facts took place in North Waziristan, on the border with Afghanistan. Until the mid-2010s, this district was a haven for militants of Tehreek-e-Taliban Pakistan (TTP), the Pakistani Taliban.

"The gunmen arrived on a motorbike and opened fire on the vaccination team," senior local police official Ashfaq Anwar told AFP, saying the attackers managed to get away.

A child was also injured by stray bullets, he said.

According to the Pakistani press, more than 70 polio vaccinators have been killed since 2012, mainly in Khyber Pakhtunkhwa province where North Waziristan is located.

Driven out of the tribal areas of northwestern Pakistan from 2014, the TTP has multiplied attacks on Pakistani soil, less deadly than in the past and mainly against the security forces, since the return to power of the Taliban in Afghanistan in august.

Polio vaccination faces lingering suspicion in Pakistan, where conspiracy theories abound that the vaccines are part of a Western plot to sterilize Muslim children.

This distrust, fueled by ultra-conservative clerics, grew after the organization of a false vaccination campaign by the CIA to find the leader of Al-Qaeda, Osama bin Laden, killed in 2011 in Abbottabad (North ).

Pakistan launched a new polio vaccination campaign on Monday, during which it plans to administer the vaccine to 12.6 million children.

In April, the country detected its first case in 15 months of this highly contagious disease, caused by a virus that invades the nervous system and can cause irreversible paralysis. Since then, 11 new cases have been identified.