The air quality in Kuala Lumpur, Selangor and Johor registered as 'unhealthy' today, according to the Department of Environment (DOE) website .

Four areas have 'unhealthy' air quality with Johor topped the list with the Air Pollutant Index (API) for its capital Johor Bahru at 119 as of 5pm. This was followed by Larkin at 107.

In Selangor, the API for its capital Shah Alam was at 102, while Kuala Lumpur was at 103.

The air quality in numerous other areas nationwide were also close to the 'unhealthy' level, such as the administrative capital Putrajaya (90), Kuala Selangor (100), Petaling Jaya (94), Gombak in Selangor (96), Country Heights in Kajang (91), Bukit Rambai in Malacca (90) and Seri Manjung in Perak (91).

According to the API, 0-50 is classified as good, 51-100 moderate, 101-200 unhealthy, 201-300 very unhealthy whereas 301 and above is considered hazardous.

Forest fires in Indonesia

The API index for Sabah and Sarawak, which were badly affected by the haze previously, was mostly at 'moderate' level. In total, 45 areas have 'moderate' air quality, while only two areas are considered 'good'.

The air quality in Malaysia has been affected by the choking smog from forest fires in neighbouring Indonesia.

Indonesian farmers burn forests annually to clear land for agriculture, causing a smokey haze that spreads around the region during the dry season, affecting tourism and causing health problems.

The government has outlawed land-clearing by fire but its weak enforcement means the ban is largely ignored.

Environment ministers from Singapore, Malaysia and other regional nations have urged Indonesia to promptly ratify a regional treaty aimed at preventing cross-border haze pollution.