World health officials have suspended a polio vaccination campaign in Pakistan after a series of attacks left eight polio vaccination volunteers dead.
The World Health Organization
and the United Nations children's agency halted work on the three-day nationwide vaccination campaign Wednesday.
The decision came after unidentified gunmen opened fire on three vaccination teams scattered across northwestern Pakistan Wednesday. Earlier in the week, attacks in Peshawar and Karachi killed six people and wounded several others. Pakistan's government has condemned the attacks.
spokeswoman Sarah Crowe says that they are "deeply saddened" by the deaths and that those killed were local workers.
"They are truly the unsung heroes of the polio eradication campaign, without a doubt. There's no way that we would be able to do anything without them. They are vitally important. And that's why the work must continue," she said.
She says that with their help, Pakistan has seen a 70 percent drop in polio cases this year.
Crowe says the local workers also help to dispel rumors that the vaccination efforts are meant to sterilize Muslims or are dangerous for children.
A Pakistani schoolgirl, who was displaced with her family from Pakistan's tribal areas due to fighting between militants and the army, receives a polio vaccine from a health worker in the outskirts of Islamabad, Pakistan, January 31, 2013.
Pakistani schoolgirls listen to their teacher, not seen, as a health worker visits their school to give them polio vaccines in the outskirts of Islamabad, Pakistan, January 31, 2013.
Pakistani schoolchildren look for their shoes while other enter a classroom as a health worker visits their school to give polio vaccines, in a poor neighborhood on the outskirts of Islamabad, Pakistan, January 31, 2013.
Pakistani relatives and mourners of a polio worker, who was killed in a roadside bomb, pray next to his body, in Parachinar, Pakistan, January 31, 2013.
A policeman stands guard as Neila gives polio vaccine drops to a child at a Christian colony slum in Islamabad, Pakistan, December 20, 2012.
A polio worker gives polio vaccine drops to a child in Lahore, Pakstian, December 20, 2012.
A policeman accompanies polio workers during their anti-polio drive mission in Lahore, Pakistan, December 20, 2012.
A health worker visits Lahore's slums to administer the polio vaccine to infants, Pakistan, December 19, 2012.
Nishat gives polio vaccine drops to a girl in Lahore, Pakistan, December 20, 2012.
A girl shows a finger marked after being immunized in Lahore, Pakistan, December 19, 2012.
And while no one has claimed responsibility for the attacks, the Pakistani Taliban have prevented such programs in the past, saying they are a cover for spying.
The Taliban began voicing opposition to Western-backed health programs after a Pakistani doctor was imprisoned for helping U.S. intelligence agents run a fake hepatitis vaccination program aimed at locating then-fugitive al-Qaida chief Osama bin Laden.
In July, armed men killed a Pakistani doctor working for the World Health Organization on a national immunization campaign.
Pakistan, Afghanistan and Nigeria are the only three countries were polio remains endemic.