KARACHI, Pakistan

Gunmen killed a policeman assigned to protect a polio vaccination team in northwest Pakistan on Monday, a police official said.

The constable was targeted while en route to join the security team in Khyber tribal district, a region bordering Afghanistan, according to local police chief Rai Mazhar Iqbal.

The attack, the latest in a series of ambushes, occurred a day after Pakistan launched a new campaign to eliminate the crippling disease.

Prime Minister Shehbaz Sharif inaugurated the first anti-polio drive of the year on Sunday in Islamabad, alongside officials from the World Health Organization (WHO) and UNICEF.

Pakistan, along with Afghanistan, remains one of the last two countries where the polio virus continues to circulate. Sharif said the country reported 77 polio cases last year.

Since 2014, the WHO has required all travelers from Pakistan to present a valid polio vaccination certificate before departure.

Polio vaccination efforts, particularly in the border regions of Balochistan and Khyber Pakhtunkhwa, have faced obstacles, with militant groups attacking polio workers and their security escorts. These groups view the vaccination campaigns as part of a broader anti-Muslim and Western conspiracy, leading to death threats against many vaccinators, especially women.

More than 150 people linked to the polio drive have been killed across Pakistan since 2012.