TodayOnline.com - A choking haze enveloped most of Singapore on Friday, sending the Pollutant Standards Index (PSI) to its highest level this year.

The PSI reading issued by the National Environment Agency (NEA) hit 80, up from the previous record of 73 last Monday, but still in the moderate range. In response, the NEA will now release an hourly update on the PSI average over a three-hour period, to give a better indication of the air quality.

The NEA reiterated that the smog is likely to clear by mid-October.

Much of the pollutant cloud is from bush fires from Indonesia and, to date, both Indonesia and Malaysia appear to be bearing the brunt of this smog attack.

Kuala Lumpur and its administrative capital of Putrajaya plummeted into the "unhealthy" range at 101 and 100 on the Air Pollutant Index (API). The API, equivalent to Singapore's PSI, considers a score of 101-200 to be unhealthy.

Unhealthy air was reported in 14 towns, including Johor Bahru and Port Klang.

In the hardest-hit states of Sarawak and Sabah, air quality was edging towards hazardous levels which begin at 301.

In Indonesia, the haze pushed schools in Kalimantan and other areas on Borneo Island to shut.

The rapidly worsening regional situation prompted Malaysia's Natural Resources and Environment Minister Datuk Seri Azmi Khalid to criticise Indonesia for not ratifying the Asean Transboundary Haze Agreement, which came into force in 2003.

Indonesian authorities accused Malaysian plantation companies operating in Sumatra and Kalimantan of burning forests to clear the land for agriculture.

The finger pointing, however, has not solved the problem — smog that perennially blankets South-east Asia still remains — though active steps are being taken to remedy the situation.