The number of Indonesian children infected with the crippling polio virus has risen to 155, with the discovery of 33 new cases in the last two weeks.

The World Health Organization says the new infections were found in areas on western Java island, where the disease originally broke out earlier this year.

The polio outbreak - Indonesia's first in 10 years - has prompted authorities to vaccinate 6.5 million children. Another 24 million will be immunized in new rounds of a vaccination campaign on August 30 and September 27.

Polio is usually spread through polluted water. It affects the nervous system, causing paralysis, muscular atrophy and death.

Some information for this report provided by AP and AFP.