Malaysia has officially declared a state of emergency in the Serian district of Sarawak state on Borneo island after the region was hit by severe air pollution, according to a report from Japan's Mainichi Shimbun on September 6. The declaration came on September 4 as thick haze from Indonesian forest fires continued to spread into neighboring countries, raising alarms across the region.

On the same day, Singapore witnessed air pollution levels reaching the "unhealthy" range for the first time in about three years, a development that prompted immediate government action. The Pollutant Standards Index (PSI) in Singapore breached the 100 mark, crossing into the unhealthy zone, a threshold not crossed since October 2023 due to haze effects. Authorities have since advised childcare centers and businesses to avoid organizing extended outdoor activities.

According to Malaysian officials, the Air Pollutant Index (API) in Serian soared to 521 on September 4, well above the 500 threshold that triggers an emergency declaration. Other areas, including the state capital Kuching, also recorded worsening air quality conditions. The deterioration has forced the closure of approximately 650 schools across Sarawak for a five-day period.

The Singapore National Environment Agency attributed the haze to wind currents carrying smoke from numerous forest and peatland fire sites in central and southern Sumatra, as well as Kalimantan in Indonesia. This year has seen widespread forest fires across multiple Indonesian regions. From January to July, the total burned area reached approximately 200,000 hectares, disrupting education for nearly 1.4 million students who were compelled to switch to online learning.