Indonesian officials have reported two new cases of polio in densely populated West Java province, bringing the total number of infected children to six.
Indonesian health authorities, working with the United Nations health agency, have been vaccinating children in the immediate area of the outbreak, just south of Jakarta.
On May 31 workers will begin to inoculate some 5.2 million children in Jakarta and the rest of western Java.
The six polio cases are Indonesia's first since 1995.
Indonesia is 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 hard-line Muslims have boycotted a vaccination campaign.