according to the BBC. The health workers were visiting homes in the city to administer the polio vaccine to young children. Militants claim polio vaccination programs are a front for spies, according to Radio Free Europe/Radio Liberty.The Pakistani Taliban have stymied vaccination efforts in many areas of the country, since it banned polio immunization in 2012. Attacks on polio workers have halted immunization in Taliban-controlled areas, causing the deadly virus to re-establish itself and spread. Credit: Radio Free Europe/Radio Liberty">