PESHAWAR, Pakistan, Dec 19, 2012 (AFP) - Gunmen in Pakistan mounted fresh attacks Wednesday on health workers carrying out polio vaccinations, taking the death toll to eight and prompting UNICEF and WHO to suspend work on a campaign opposed by the Taliban.

Pakistan is one of only three countries in the world where polio is still endemic. But efforts to stamp out the crippling disease have been hampered by resistance from the Taliban, who have banned vaccination teams from some areas.

Eight people working to immunise children against the highly infectious disease have been shot dead in Pakistan since the start of a three-day UN-backed nationwide vaccination campaign on Monday.

In the latest attack Wednesday, a female health worker and her driver were shot dead in Charsadda near Peshawar, the main town in the northwest, police official Wajid Khan told AFP. A second police officer confirmed the incident.

Another worker was shot and critically wounded while giving out polio drops earlier on Wednesday on the outskirts of Peshawar.

After reporting the man's death, doctors at the city's Lady Reading Hospital later said he was being kept alive on life support equipment.

You can watch a report on the attacks below:

"Medically he is dead but we have put him on a mechanical ventilator. This is our last try for his life but he is not responding," Abdul Qadir, neurosurgeon in the hospital's intensive care unit, told AFP.

Two other polio teams were targeted in similar attacks in the towns of Nowshera and Charsadda, police and health officials said, but the workers escaped unharmed. One passer-by was slightly injured in Nowshera.

Violence has blighted every day of the polio campaign so far: one health worker was shot dead in Karachi on Monday and four more were killed in the city with another gunned down in Peshawar on Tuesday.