Gunmen in Pakistan mounted fresh attacks Wednesday on health workers carrying out polio vaccinations, taking the death toll to nine 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.
Nine people working to immunize 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 also died, doctor Ahmad Saqlain of the city's Lady Reading Hospital 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 polio workers escaped unharmed. One passerby 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.
The bloodshed prompted the UN children's agency Unicef and the World Health Organization to suspend work on polio campaigns across Pakistan.
Unicef spokesman Michael Coleman said the two organizations halted work in Sindh and Khyber Pakhtunkhwa provinces after Tuesday's attacks but had now extended the suspension nationwide.
Rumours about polio drops being a plot to sterilize Muslims have long dogged efforts to tackle the disease in Pakistan, but suspicion of vaccination programs intensified after the jailing of a doctor who helped the CIA find Osama bin Laden in 2011 using a hepatitis campaign.
Polio cases in Pakistan fell to 28 in 2005 but have risen sharply in recent years, hitting 198 in 2011 – the highest figure for more than a decade and the most of any country in the world last year, according to the World Health Organization. There have been 56 infections so far in 2012.
There has been no claim of responsibility for this week's attacks, but in June the Taliban banned immunizations in the tribal region of Waziristan, condemning the polio campaign as a cover for espionage.
In Waziristan, a hub for Islamist militants, the ban – also enforced as a protest against US drone strikes – has put the health of 240,000 children at risk, officials say.
Police said Tuesday's killings in Karachi took place in suburbs dominated by Pashtuns, the dominant ethnic group in northwest Pakistan who have a sizable migrant population in the city.
Pashtuns are also disproportionately affected by polio: though the community makes up only 15 per cent of the population, it accounts for three quarters of polio cases, the WHO says.