Militants today attacked a team of polio vaccinators in the restive Bajaur tribal region of northwest Pakistan, killing a security personnel.
The members of the polio vaccination team were unharmed, officials were quoted as saying by TV news channels.
The attackers gunned down paramilitary personnel protecting the vaccinators.
Pakistan is one of only three countries where the polio virus is endemic.
Taliban factions in the country’s north-west have banned polio vaccination campaigns over the past two years.
Health experts have estimated that thousands of children have been left vulnerable to polio in Khyber-Pakhtunkhwa province and the tribal areas.
In April, a policeman was killed and another seriously injured when militants attacked a team of polio vaccinators in Mardan town of Khyber-Pakhtunkhwa.
In January, six women and a man working for an NGO involved in the polio vaccination campaign were shot dead in Swabi district.
In December, eight volunteers involved in a polio vaccination drive were gunned down in a string of attacks in the southern port city of Karachi and Khyber-Pakhtunkhwa.
The attacks prompted UN agencies to withdraw their workers from the campaign.