The Natural Resources and Environment Ministry is investigating seven hotspots detected in Sarawak by a National Oceanic and Atmospheric Administration-18 (NOAA) satellite image yesterday.

Its minister Datuk Seri G. Palanivel said the government would not hesitate to take necessary action on those responsible for open burning after the investigation was completed.

According to the website http://apims.doe.gov.my, the Air Pollutant Index (API) as at 6pm in Sibu, Sarawak was 135, or unhealthy.

Sri Aman and Samarahan recorded API readings of 99 and 92 respectively, both considered moderate but almost reaching unhealthy level Palanivel said the NOAA-18 also showed 98 hotspots in Sumatra and another 52 in Kalimantan, Indonesia.

"A report from the Asean Special Meteorological Centre (ASMC) showed movement of haze from the area of fire in Sumatra and West Kalimantan in Indonesia to southern Sarawak," he said in a statement here today.

API readings of between zero and 50 is categorised as good; moderate (51-100); unhealthy (101-200); very unhealthy (201-300) and hazardous (over 301).