At least six polio vacci for government campaign to eradicate disease killed in separate attacks in Karachi and Peshawar Gunmen in Pakistan have killed six women who were working on a campaign to vaccinate children against polio. Five of the women were killed in the country's largest city, Karachi. Islamabad is in the middle of a three-day vaccination drive targeting high risk areas of the country as part of an effort to immunise millions of children under the age of five. Though the Taliban have previously criticised polio efforts in the nation, no group has taken responsibility for Tuesday's deaths. Al Jazeera's Imtiaz Tyab reports from Islamabad.