The Bangladesh government says it will immunize 24 million children against polio in a huge nationwide operation Saturday.

The Health Ministry says it will mobilize 700,000 volunteers at 140,000 vaccination centers to immunize children age five and under. Medical workers are setting up temporary centers in such locations as train stations and bus terminals.

After a six-year absence, polio returned to Bangladesh in January last year. Since then, 17 cases of the potentially crippling disease have surfaced in the country, despite an anti-polio drive the government started last April.

Health officials believe the disease spread from neighboring India, which had several hundred cases in 2006, the most of any country in the world. A global drive to eradicate polio has eliminated it from all but a handful of Asian and African countries.