Air quality in Malaysia's eastern state of Sarawak has dropped to unhealthy levels, prompting authorities to close down more than 400 schools in the region.
Malaysia's national disaster management agency (NADMA) said it had sent 500,000 face masks to the state to combat the haze spread from forest fires in neighbouring Indonesia.
Authorities in Singapore also said air conditions could reach unhealthy levels over the next 24 hours if the wind kept bringing smoke from Indonesia.
They have advised anyone feeling unwell to seek medical attention.
Meanwhile, Indonesian authorities have sent thousands of military and police to douse the forest fires raging across parts of Sumatra island and the province of Kalimantan on Borneo.
At least 14 killed in explosion at weapons depot in Syria
US hits five Iranian oil tankers after attack on Navy ships
UK gives air traffic provider a week to probe outage that halted flights
Serbia's President Vucic dissolves parliament, calls snap elections
With large crowds attending, Norway lays King Harald to rest
Jordan intercepts 18 Iranian ballistic missiles
Air traffic control issue disrupts flights at major UK airports
At least 73 injured after Houthi rebels attack Saudi civilian and energy facilities
