The haze has once again returned to haunt Kuala Selangor and Port Klang with the air quality once again rising to 'unhealthy' levels.

According to the Air Pollutant Index (API) released by the Department of Environment (DOE), Kuala Selangor registered 125 while Port Klang 102.

As of 11am, 21 areas were recorded with 'good' air quality while another 26 were 'moderate'.

When contacted, Meteorological Department spokesperson Zaridah Mohd Jaal said the cause of the haze is unknown.

"Yesterday, there were only a few recorded hot spots in Sumatra and peninsular Malaysia. There were nine in Sumatra and only one in the peninsular," she said.

The API readings at 11am are an average value for the past 24 hours. The hotspots statistics for today will be available after 6pm.

Hot spots

Asked if the situation is expected to deteriorate over the coming weeks, she said it would depend on the situation in Sumatra.

"Currently the winds are blowing southwesterly. If the hotspots in Sumatra increase, then the haze would probably come back," she added.

Meanwhile, Zaridah said she was unaware of the situation in Rokan Hilir, Sumatra.

Yesterday, Bernama reported that thick smoke had been emerging from forest fires in the Riau province of Indonesia for the past three days.

According to the report, the Meteorological and Geophysical Office in Pekanbaru, capital of Riau, detected 33 hot spots in Sumatra on Sept 13. Most of the hotspots were concentrated in Rokan Hilir.

Last month, the haze shrouded several states across the Malaysian peninsular while air quality reached hazardous levels (API reading 300 or more) in Port Klang and Kuala Selangor, prompting the government to declare a state of emergency in the two areas.