Islamabad, Pakistan (CNN) -- Gunmen fired on two female health workers administering polio vaccines in northwest Pakistan on Tuesday, killing one and wounding the other.
The shooting on the outskirts of Peshawar was the latest in a series of deadly attacks against those giving out the vaccine.
Two men on a motorbike opened fire on the two women while they were going house to house in the village of Bedh Der, said local police official Shafi Ullah.
One woman died at the scene; the other was critically injured, Ullah said.
Pakistan is one of three countries in the world where polio has yet to be eradicated.
Pakistanis have viewed polio vaccination campaigns with suspicion after the CIA's use of a fake vaccination program in 2011 to collect DNA samples from residents of Osama bin Laden's compound to verify the al Qaeda leader's presence there.
Bin Laden was killed by U.S. forces in May 2011.
In June, a Taliban commander in northwest Pakistan announced a ban on polio vaccines for children in the region as long as the United States continues its campaign of drone strikes in the region, the Taliban said.
It wasn't immediately clear if the Taliban played a role in Tuesday's attacks.
Polio, a highly infectious viral disease that can cause permanent paralysis in a matter of hours, has been eradicated around the world except for three countries where it is endemic: Pakistan, Nigeria and Afghanistan.
After the number of cases spiked sharply last year, Pakistan stepped up its eradication efforts. The numbers fell from 173 in 2011 to 58 in 2012, according to the Global Polio Eradication Initiative.