LAHORE, Pakistan (AP) — A Pakistani health official says a special anti-polio drive has been launched in the country's eastern Punjab province.

Imran Nazir says the week-long campaign was launched on Monday amid tight security.

He says thousands of workers are taking part in the drive by going house-to-house to vaccinate children in the struggle to eradicate the crippling disease.

Pakistan, Afghanistan and Nigeria are the only three countries left in the world where polio has not been eliminated.

Pakistan regularly launches anti-polio drives despite threats from the Taliban who perceive the campaign as part of a Western conspiracy and claim it will sterilize Pakistani children.

The Taliban and other militants have in the past attacked polio vaccination teams, health centers and health workers, even security forces accompanying health workers during the campaign.