More than 25 million Indonesians on Sumatra and Borneo islands are exposed to smog caused by forest and plantation fires, an official said today.

Six provinces on Sumatra and Borneo have declared haze emergencies and advised residents to stay indoors, said Tri Budiarto, emergency response deputy at the National Disaster Management Agency.

Budiarto said three aircraft and 13 helicopters had been deployed to the affected areas to seed rainclouds and drop water.

“We are hoping land and aerial fire-fighting efforts will be able to suppress the fires and haze,” Budiarto said.

The haze from Indonesia has also travelled to Malaysia and southern Thailand.

The practice of open burning to clear land is illegal but is common in Indonesia.

The government has warned that the El Nino weather phenomenon, which is expected to last until October, would result in an extended dry spell and more forest fires in Indonesia.

The Agriculture Ministry has predicted that El Nino could damage 200,000 hectares of rice fields, or about 1-2 million tonnes of rice crops.

- dpa