Bannu- Hardliners and illiterate people of Bannu today made two lady health workers hostage, who were busy in anti-polio campaign in the area. According to media reports, this incident took place in Mamakhel area of Bannu, where people trashed equipment and vaccination kits were snatched from lady health workers. The hardliners also abducted two female campaigners who were later released on request of elders of the area on assurance that they would never come in the area to anti-polio campaign. It may be mentioned here that anti-polio teams are being attacked in almost every province of the country since last year or so. Seeing the situation, the government has decided to provide better security facilities to the workers. Some 56 people have been killed in militant attacks on anti-polio teams in Pakistan since December 2012. Militant groups such as the Pakistan Taliban oppose immunisation, saying it is a cover for US spying. Violence, and the threat of it, have badly hampered a campaign to stamp outpolio in Pakistan, which along with Nigeria and Afghanistan are the only countries where the disease remains endemic. The WHO has warned that Peshawar is the world s "largest reservoir" of the wild polio virus.