Officials had pinned their last hopes of inoculating children in the northwestern district on talks with tribesmen, which were successively delayed until Wednesday, the last day of the nationwide campaign."Polio vaccination will be banned until drone attacks are stopped," tribal elder Qadir Khan told a gathering of more than 200 elders and Islamic scholars in Miranshah, the main town of North Waziristan."Drones martyr so many children, while polio afflicts one or two out of hundreds of thousands," said tribal elder Maamoor Khan.North Waziristan administrator Siraj Ahmed Khan said he had sought to convince the tribesmen to accept the vaccinations for the disease, which leaves children crippled for life."Polio is rampant in tribal areas and government desires to prevent its spread," Khan told the meeting.The polio battle exemplifies the government's limited writ over the tribal belt.Hafiz Gul Bahadur, whose followers are fighting Western troops in Afghanistan, and the Pakistani Taliban banned vaccinations in North and South Waziristan, risking the health of 240,000 children.They demanded an end to US drone strikes and condemned the campaign as a cover for espionage. A Pakistani doctor was jailed in May after helping the CIA find Osama bin Laden using a hepatitis vaccination programme.Officials said that a further 110,000 children in the tribal district of Khyber also risked going without the vaccine, because of fighting between government troops and Mangal Bagh.The prime minister's office told AFP that the campaign would be extended until Thursday and Friday in the rest of Pakistan, but said there had been "no change" on the situation in Waziristan.The highly infectious disease affects mainly the under-fives and can cause paralysis in a matter of hours. Some cases can be fatal.The Lancet medical journal has said vaccination problems last year led to Pakistan's highest number of polio cases in a decade, 198, compared to 144 in 2010.