Syria, Yemen, and Somalia are categorized as very-high-risk, and Iraq, Sudan, and Libya are categorized as high-risk, while Pakistan and Afghanistan are the only countries in which the disease remains endemic as of 2019. Since 2007, people administering polio vaccines have been the target of violence in Pakistan. A 2011 US Central Intelligence Agency operation used a hepatitis vaccination program as a cover to search DNA evidence to confirm the location of Osama bin Laden. Following his killing the same year, Islamist insurgents in the region have become more hostile to vaccination efforts. More recently, the hostility has been exasperated by the United States' expansion of the use of drone strikes in northwest Pakistan; in June 2012, Mullah Nazir, leader of the Federally Administered Tribal Agencies, distributed leaflets calling for a ban on polio vaccination with the goal of persuading the US to stop drone strikes in the area.