Malaysian authorities categorise Air Pollution Index (API) readings above 300 as hazardous, with a measurement of 500 the threshold for declaring an emergency.

Sarawak, in Kalimantan, has been heavily affected by fires on the Indonesian side of the island, with haze forcing school closures in some parts of the state.

KUCHING, Sept 4 — Haze in Serian worsened sharply overnight, with the Air Pollutant Index (API) there climbing to 495 this morning, just five points below the level that would...