The haze has caused the diversion of five flights and delay of nine in Sarawak, according to Malaysia Airports Holdings Bhd.

MAHB, in a Facebook post, advised airline passengers to check their flight schedules with the respective carriers.

It said the haze in Kuching was bad and visibility was 2,000metresas at 4 pm Thursday.

As at 5 pm, according to the Department of Environment website, the Air Pollutant Index reading in Sarikei was 104 compared to 99 at 1 pm.

Three other areas in Sarawak still recorded API at unhealthy levels, namely Samarahan (167) Sri Aman (154) and Kuching (146).

API readings of between 0 and 50 indicate good air quality; between 51 and 100, moderate; between 101 and 200, unhealthy; between 201 and 300, very unhealthy; and over 301, hazardous.