KUCHING/PALEMBANG - The haze in some parts of Sarawak state worsened on Thursday (Sept 10), recording unhealthy air pollution index (API) readings.

As at noon, the API for Samarahan - the worst hit area in Malaysia - rose to 175, according to the Meteorological Department website. The API for Sri Aman was 151 and Kuching was 149.

The rest of Sarawak recorded moderate air quality level.

An API reading of between 0 and 50 is categorised as good, while 51 to 100 is moderate; 101 to 200 (unhealthy), 201 to 300 (very unhealthy), and 300 and above (hazardous).

In Sabah state, three areas recorded moderate API readings - Keningau (68), Tawau (66) and Kota Kinabalu (64). Only Sandakan has good air quality (46). The whole of Johor recorded moderate air quality as at noon, ranging from 55 to 84.

Good API readings were recorded in areas like Putrajaya, Batu Muda and Cheras, Kedah, Kelantan, Negeri Sembilan, Selangor and Perak.

In Indonesia, the pollutant index in Palembang, South Sumatra, worsened to hazardous level, prompting the city administration to order school closure till at least Saturday (Sept 12).

Authorities planned to deploy more than 1,000 soldiers to Palembang to help with firefighting efforts.

The air quality in Dumai, Riau province, improved after rainfall on Wednesday. The haze there was no longer at hazardous level, though still very unhealthy. The city's Pinang Kampai airport had been closed.

The haze is a result of widespread clearing of forests in Indonesia for oil palm plantations. Not only does it affect neighbouring countries such as Malaysia and Singapore, but it also makes life miserable for about 22.6 million residents in Sumatra and three million in Kalimantan.