Indonesia says another child on Java Island has been diagnosed with polio.
Health officials say the new case, a 20-month-old girl, is in the same district where an 18-month-old boy was diagnosed with the disease.
They are Indonesia's first confirmed cases of polio since 1995.
Jakarta is preparing to vaccinate at least five million children in the region.
Indonesia is now the 16th country where polio has reappeared since 2003, and the first outside Africa and the Middle East.
The outbreak has been traced to northern Nigeria, where Muslim clerics triggered an immunization boycott, claiming the polio vaccine was contaminated in a plot by Western nations to sterilize Muslim girls or spread AIDS.