KARACHI, Pakistan

Gunmen on Sunday killed a policeman guarding polio vaccinators in northwestern Pakistan, police reported.

The incident – the latest in a string of attacks targeting vaccinators – took place in Kohat in the northwestern Khyber Pakhtunkwa province, which borders neighboring Afghanistan.

Khalid Suhail, a city police chief, told reporters that suspected militants riding a motorbike targeted a polio vaccination team on the outskirts of Kohat, killing a constable assigned to protect the team.

The members of the vaccination team remained unhurt, he added.

There was no immediate word of responsibility for the attack. However, the Tehreek-e-Taliban Pakistan (TTP), a consortium of several militant groups in Pakistan, has long been targeting vaccination teams across the country, claiming the vaccination campaigns are a Western conspiracy to sterilize children.

The government has launched a fresh anti-polio vaccination campaign across the province in an attempt to eradicate the crippling disease.

No fresh polio case has been reported for some time in this South Asian nuclear country, which hopes to eradicate polio by the end of 2021.

Pakistan and Afghanistan are the only two countries in the world where polio virus still exists, and the country remains under a polio-linked travel restriction imposed by the World Health Organization (WHO).

In 2014, the WHO made it mandatory for all people traveling from Pakistan to carry a polio vaccination certificate.