Singapore ordered immediate closure of schools as air quality becomes worse due to thick smogs from Indonesian forest fires.

Residents are advised to remain indoors due to hazy conditions brought about by the denser haze from Sumatra “blown in by the prevailing southerly winds,” according to the National Environment Agency (NEA) advisory.

In the NEA report, the Pollutant Standard Index (PSI), or air quality, is in the “very unhealthy range” and is to date, “the highest 24-hr PSI recorded in 2015.”

As reported by Asia One, the haze has been present for three weeks now and is said to be “the worst such episode since mid-2013 when the air quality reached hazardous levels.” Singapore and Malaysia were the affected countries back then.

NEA’s forecast tells that for the next 24 hours, it would be expected that it would still be in its hazardous level.

Upon consultation with the Ministry of Health, the Ministry of Education of Singapore has ordered the closure of primary and secondary schools as well as MOE Kindergartens and Special Education schools in the country.

However, “all Junior Colleges, Centralised Institute and Post-Education Institutes (PSEIs) namely the Autonomous Universities, Polytechnics and ITEs, will remain open” and that there would be “no national shut-down of workplaces”, as posted on Singapore Government’s website.

In a Yahoo! News report, Singapore Prime Minister Lee Hsien Loong has ordered the distribution of face masks at different community centers. Similarly, in a Facebook post, Lee advised that “employers should not compromise on the health and safety of their employees.”

Indonesian President Joko Widodo has launched probes to investigate companies whose operations could have caused the forest fires and instructed to revoke the license of those who are deemed liable.

Meanwhile, Centre for International Forestry Research scientist Herry Purnomo believes that Singapore and Malaysia should share the responsibility for the fires as both countries are “carbon credit buyers” and benefit profit from Indonesia’s palm oil, as reported in The Sydney Morning Herald.