The Indonesian president, Susilo Bambang Yudhoyono, has apologised to Singapore and Malaysia for record-setting pollution caused by forest fires in his country.

"For what is happening, as the president, I apologise to our brothers in Singapore and Malaysia," Yudhoyono said. He asked for their understanding and said Indonesia was working hard to fight the fires which are often set by farmers to clear fields.

Jakarta has dispatched planes and helicopters to battle the blazes in peat swamp forests as well as plantations in Riau province on the island of Sumatra, where the smoke easily drifts across the sea to the two neighbouring countries.

Speaking at a news conference after a cabinet meeting to discuss the issue, Yudhoyono said he had ordered an investigation into the fires.

"There should be a thorough investigation. In my analysis, there are both natural and human factors," he said, adding that the wind direction had caused the smoke to concentrate in Singapore and Malaysia.

Malaysia declared a state of emergency on Sunday in a district where the haze triggered one of the country's worst pollution levels, while Singapore has urged citizens to remain indoors because of "hazardous" levels of pollution.

In Indonesia, media reports said two commercial flights to Pekanbaru, Riau's provincial capital, were diverted on Monday to Kuala Lumpur and North Sumatra's capital, Medan, while another had to fly back to Singapore.

In Dumai in Riau, dozens of houses were burned down by forest fires, and a leopard with leg injuries fled from a forest into a village. Conservationists assisted by villagers took seven hours to capture the animal, which refused to return to the forest. It was being cared for at the state conservation office.

Indonesia's National Disaster Management Agency said aircraft and firefighters extinguished 265 fires in Riau on Monday.

Last week, the Indonesian co-ordinating minister for people's welfare, Agung Laksono, slammed critical comments by Singaporean officials about the haze, saying they should have been conveyed through diplomatic channels instead of publicly.

"Singapore should not act like children, making all that noise," he said.