Hundreds of thousands of people have fled North Waziristan since the launch of a government offensive on June 15 against the Pakistani Taliban in the tribal areas bordering Afghanistan . WHO warns Pakistan 's growing refugee population at risk of polio . The number of displaced could reach 300 in the northwest . North Waziristan , where the army is killing civilians , has the most refugees . It is highly infectious and ca n't be treated , but is preventable with a vaccine .
WHO warns Pakistan 's growing refugee population at risk of polio . The number of displaced could reach 300 in the northwest . North Waziristan , where the army is killing civilians , has the most refugees . It is highly infectious and ca n't be treated , but is preventable with a vaccine .