Air quality deteriorated today in Kuala Lumpur after it was hit by haze, the country's environment department said.

The air pollution index in Kuala Lumpur rose from 69 on Monday evening to 83 on Tuesday morning, the department said.

A reading between 101 and 200 on the index is classified as "unhealthy", while a moderate reading is between 51 and 100.

Air quality today remained at near-unhealthy levels in an area east of the capital, where the reading was 91.

In western Port Klang the reading was 89, while in several other western areas it was at moderate levels.

Coastal areas in northern and western Malaysia were hit by an acrid haze yesterday after winds brought over smoke from fires in Indonesia.

91 hotspots detected

A forecaster with the Meteorological Department, Kamil Ibrahim, said rains last evening had cleared the air but hazy conditions from fires in Indonesia's Sumatra and Borneo island, as well as Malaysia, could return.

"The rains yesterday cleared the air in most of the hazy parts of the country but whether it lasts, it depends on the wind conditions and the hotspots in neighbouring countries," Kamil told AFP .

"It depends on the hotspots, since yesterday there were 91 hotspots detected in Sumatra and in Borneo island, including Sabah and Sarawak," he said, referring to the east Malaysian states also on Borneo.

Burning in Indonesia and some parts of Malaysia to clear land for crops causes an annual haze that afflicts countries in the region, including Singapore and Thailand.