PESHAWAR: Unidentified gunmen shot dead a police officer escorting a team of polio workers in northwest Pakistan's restive Khyber Pakthunkhwa province on Monday, the second such incident in two days.
The officer was killed by the unknown gunmen riding a motor cycle while he was joining the polio workers in the tribal district of Dera Ismail Khan bordering South Waziristan, police said.
A search operation to arrest the killers is underway, they said.
The attack took place a day after bike-borne gunmen fired at a police constable in the Daudzai area of Peshawar district and fled from the scene.
The policeman was returning home after being with a polio team when he came under fire, police said.
Polio health workers and law enforcement officials who are tasked with providing security have often been targeted by militants and miscreants in Pakistan.
Last week, the federal government had announced to launch a nationwide five-day polio immunisation drive from August 2 to inoculate 23 million children against the crippling disease.
Prime Minister Imran Khan on June 24 expressed hope that Pakistan will become polio-free in the next year.
Taking to Twitter, Khan said only one case of the crippling disease had been reported this year so far, adding: "We will eradicate polio completely in coming yr".
Pakistan and neighbouring Afghanistan are the only two remaining countries in the world where polio is endemic after Nigeria was declared free of poliovirus last year.
The Pakistan government has suspended the anti-polio drive and post-campaign evaluation in the past following the increasing number of attacks on polio workers in different parts of the country.
Attempts to eradicate the crippling disease have been seriously hampered by deadly targeting of vaccination teams in recent years by militants, who oppose the drives, claiming that the polio drops cause infertility.