Gunmen killed four health workers who were part of a polio vaccination team in Pakistan on Wednesday, an attack that highlights the risks of fighting the disease across the country.
Extremist violence has long threatened efforts to curb polio in Pakistan, where the deadly virus remains endemic. Militants have killed hundreds of health workers who have attempted to administer the vaccine.
No one immediately claimed responsibility for Wednesday's attack, but Taliban militants have repeatedly targeted health workers to prevent polio immunization. The militants accuse them of being Western spies or of distributing vaccines designed to sterilize children.
The vaccination team was waiting for a police escort when two gunmen opened fire on them in the southwestern city of Quetta, The Associated Press reports. Three Pakistani women and their driver were killed.
A local police official told The New York Times that three other female workers were wounded in the attack. They were admitted to a hospital, The Times reports, and their condition was said to not be life-threatening.
The vaccination campaign in Quetta was halted immediately after the attack, but officials said it would continue in other districts of Baluchistan Province.
Polio cases in Pakistan stand at a 15-year high – the World Health Organization (WHO) has already registered 235 polio cases since January. Pakistan, along with Nigeria and Afghanistan, are the only countries in the world that have never stopped transmission of the disease.
Polio, which can cause paralysis and death, was nearly eradicated across the globe two years ago. But Pakistan has remained an epicenter of the disease. The majority of re-infected countries – including Syria, China, Israel, and Egypt – can trace the virus back to there.
One reason for polio's spike in Pakistan is the military campaign in North Waziristan, a remote mountainous region along the Afghan border, The Christian Science Monitor reported earlier this year. Frequent drone strikes and Army operations against militants in the region have forced a large number of unvaccinated children to flee their homes and move around the country.
The Monitor reported that one of the biggest problems was the lack of government support and health services in the Federally Administered Tribal Area (FATA).
There have not been any polio immunization campaigns in FATA's North Waziristan district in the last two years, says Khalid Aziz, the former chief secretary of KP Province who has studied FATA. Other districts within the FATA tribal belt have not seen visits from vaccination teams for four years.
With no local representation, courts, police stations, or basic state infrastructure including schools and hospitals, the government fails to carry out its role as a service-provider in the area.
"This has created an environment where an entire segment of the Pakistani population is cut off from the rest of the country and the rest of the world. Myths flourish, and the state fails to meet the most basic needs of its citizens," says Aziz.
The Independent Monitoring Board, which advises agencies fighting polio, harshly criticized Pakistan's government in a report last month. The report called its complacency in fighting polio "disastrous," warning that the country risked re-infecting the rest of the world.
"It's frustrating. Eradicating polio is not rocket science," Elias Durry, head of the WHO's polio campaign in Pakistan, told Reuters.