A Pakistani militant group threatened action on Saturday against anyone conducting polio vaccinations in the region where it is based, saying the healthcare drive was a cover for US spies.
The group, based in North Waziristan and led by Hafiz Gul Bahadur, said it had banned vaccinations for as long as U.S. drone aircraft continued to make missile strikes in Pakistan.
It cited the case of Shakil Afridi, the doctor who, Pakistani sources say, helped the CIA find Osama bin Laden through a vaccination drive in the town where he was living.
"As long as drone strikes are not stopped in Waziristan there will be a ban on administering polio jabs," said the group, which is believed to have an unofficial non-aggression pact with the Pakistani military.
"No one will have the right to complain about damage in case of any violation ... Polio campaigns are also used to spy for America against the mujahideen (holy warriors), one example of which is Dr. Shakil Afridi," it said in a statement.
Afridi ran a vaccination campaign and used cheek swabs to try to gather DNA from bin Laden's children, said one former Pakistani security official familiar with the case.
He and other health workers went to bin Laden's house in the town of Abbottabad and told his wives that a vaccination programme was under way in the area, the former security official said. The al Qaeda leader was killed in the raid by US special forces last year.
Pakistan is one of the few countries that still harbours the polio virus, including a strain found nowhere else in Asia, but some clerics have condemned the vaccine, putting thousands of people off vaccinating their children.
The Afridi case has deepened suspicions among some Pakistanis that the United States is using health programmes to spy in the country where anti-American sentiment runs high.
Hero or Villain
Last month, a tribal court imprisoned Afridi for 33 years for what officials initially said was his role in the bin Laden raid. A court document later released to the media said that he was convicted for aiding a militant group.
Afridi is being held in solitary confinement in a prison in the city of Peshawar for fear that he may be targeted by Islamic militants also incarcerated there, prison sources said.
He had been working with the CIA for years before the bin Laden raid, providing intelligence on militant groups in Pakistan's unruly tribal region, said the former security official and a former Pakistani intelligence official.
U.S. officials have hailed Afridi, aged in his 40s, as a hero for helping pinpoint bin Laden's location.
Afridi's family and lawyers say he was not guilty of any wrongdoing.
The bin Laden raid, kept secret from Pakistani authorities, was a humiliation for the powerful military and raised questions about whether it was harbouring militants.
Washington and Islamabad are now in deadlock in negations over the re-opening of supply routes to NATO troops in Afghanistan which Pakistan shut in November to protest against the killing of 24 of its soldiers in a NATO raid.
Washington has rebuffed calls for an apology for the air strike and Defense Secretary Leon Panetta has said the United States is at the limits of its patience over safe havens for militants in Pakistan who carry out attacks in Afghanistan.
Pakistan has denied backing militant groups seeking to topple the Kabul government.