Balikpapan – Wildlife officials said Saturday that they had found the charred remains of dozens of rare animals in a national park in eastern Borneo, where forest fires are burning.

Doctors warned people, meanwhile, to expect an increase in upper respiratory tract infections if thick smoke and haze from the fires continue to build near the cities of Balikpapan and Samarinda, about 750 miles northeast of Jakarta.

"We could face major health problems if it does not rain soon," said Dr. Jusuf, head of a state-run hospital in Samarinda.

The fires have been burning as a drought grips the eastern part of Borneo island, which should be having heavy rains at this time of year. Meteorologists blame the El Nino weather phenomenon for the delay of the wet season.

Last year, hundreds of fires between July and November across Indonesia produced a haze over much of Southeast Asia, threatening the health of millions. The new fires in Borneo have raised fears the haze might return, perhaps even worse than the last time.

As in 1997, officials say that many of the fires have been started deliberately by farmers as well as plantation and forestry companies to clear land cheaply.

The official Antara news agency reported that rangers in the Kutai National Park, north of Samarinda, had found a large number of remains of orangutans, small deer, snakes and porcupines.

Fires have also broken out in the Bukit Suharto conservation park, south of Samarinda.

Earlier this week at least eight orangutans, including four babies, were saved by wildlife officials after parts of their natural habitat were burned.

Two other orangutans were found dead in traps. Mother apes sometimes are hunted by villagers who take their young to sell as pets.

The government estimates at least 34,600 acres of forest have been burned since January.