Indonesian rangers today were struggling to put out forest fires which have created a choking haze that has also cloaked parts of neighbouring Malaysia, but there were too few to tackle the annual problem, officials said.

They said the haze that has cloaked Kuala Lumpur and most of its surrounding areas since Tuesday was caused by ongoing illegal land clearance by farmers on Sumatra island and Kalimantan, the Indonesian part of Borneo.

"There are not enough forest rangers here and the ones available are already too busy trying to douse fires," said Giri Darmoko of the West Kalimantan meteorological agency office in Pontianak.

Due to the shortage of rangers, most fires were left to burn themselves out.

"We can only urge farmers and land owners to temporarily stop making fires," Darmoko told AFP .

Staying indoor

Haze in Pontianak was at its worst from midnight until early morning, forcing people to stop morning outdoor sports activities, he said.

Visibility was down to 500 meters at 7:00 am but airport officials said it later improved enough not to hamper flights.

About 46 hotspots caused by forest fires and land clearance were detected around Pontianak and in Sambas district, near Malaysia's Kuching town in neighbouring Sarawak, Darmoko said.

Meteorological officials had detected hotspots and reported similar haze problems in Sumatra's Riau province, which faces peninsular Malaysia, said Maman, a meteorological official in Jakarta.

Malaysian officials have advised residents to stay indoors and ordered hospitals to remain on alert for an increase of respiratory problems, coughs, sore throats and eye irritations caused by the haze.

"It is regrettable that people here remain ignorant about the negative impact of their land-clearing activities on our Malaysian neighbours," Darmoko said.

Falling on deaf ears

But calls urging farmers to stop land clearance fell on deaf ears.

"They are not even intimidated about facing possible fines. This is an old problem that has become an annual headache," he said.

Haze caused by fires in Indonesia and Malaysia is a common occurrence during hot, dry seasons.

In 1997 and 1998, choking haze caused mainly by Indonesian forest fires enveloped parts of Southeast Asia including Malaysia for months.