Indonesia arrests 72 as wildfires burn 285,000ha and haze shuts 600 schools in Sarawak

Indonesian authorities have arrested 72 people suspected of deliberately starting forest and land fires, as the country's worst wildfire season since 2015 scorched about 285,000ha of forests, peatlands and agricultural land through August. The fires generated toxic haze that crossed into neighbouring Malaysia, forcing nearly 600 schools in Sarawak to close and affecting about 200,000 students.

The national police spokesman said the arrests were linked to 89 forest and land fire cases across five provinces in Borneo and four in Sumatra. Most of those detained are accused of deliberately burning land to clear areas for plantations at lower cost — a practice prohibited under Indonesian law but which has persisted through successive fire seasons because of the economic incentives it offers smallholders and plantation companies.

Investigators are tracing financial records to determine whether companies financed or ordered the land clearing, suggesting the probe could widen beyond those already arrested. "We will not stop at the perpetrators on the ground," a national police official said at a news conference in Jakarta on Sunday.

The scale of the 2026 fire season has alarmed Indonesian officials and international monitors. Indonesia's Forestry Ministry detected 11,908 fire hotspots nationwide within a 24-hour period last week, up from 6,352 the previous day — nearly double the number as the crisis intensified.

FireWatch, a satellite monitoring platform developed by forest monitoring organisation Nusantara Atlas, had recorded more than 154,000 hotspots across Indonesia as at Aug 11. That was a 60% increase from July and already exceeded the totals recorded at comparable points during the severe 2019 and 2023 fire seasons.

Forest monitoring organisation Madani Berkelanjutan estimated that about 182,000ha burned in July alone — nearly twice the area scorched during the entire first half of the year — before the escalation in August pushed the cumulative total towards 285,000ha.

The total has already surpassed the areas burned in 2019 and 2023, both years marked by serious regional haze emergencies. However, it remains well below the catastrophic 2015 season, when more than 600,000ha burned during an El Niño event that brought extreme dryness across the archipelago.

Forestry Minister Raja Juli Antoni told a parliamentary hearing that by mid-August, the intensity of the current El Niño index had already exceeded 2015 levels. This alarmed officials given the scale of damage caused by the 2015 fires.

Indonesia's Meteorological, Climatological and Geophysical Agency, or BMKG, warned that August and September were expected to be the most critical months of the 2026 fire season, with peak dryness and strong winds creating favourable conditions for fires to spread rapidly.

Firefighting operations have been significantly expanded. Thirty helicopters have been deployed for water-bombing and aerial surveillance over Kalimantan, while another 22 are operating over Sumatra. The combined 52-aircraft response reflects the geographical scale of the crisis across Indonesia's two largest island groups.

Authorities have also resumed cloud-seeding operations over Kalimantan in an effort to bring rain to the worst-affected peatland areas. BNPB chief Suharyanto warned that peatland fires were particularly difficult to extinguish, even when they appeared to have gone out on the surface, as embers could continue smouldering underground.

"Fires that appear extinguished on the surface may still contain embers underneath, so sufficient rainfall is crucial to rewet the peat and fully suppress the fires," he said.

The six provinces receiving priority firefighting attention are Riau, Jambi and South Sumatra in Sumatra, and West Kalimantan, Central Kalimantan and South Kalimantan in Borneo. All contain extensive peatlands which, once ignited, are exceptionally difficult and costly to extinguish.

West Kalimantan has emerged as the worst-affected province, accounting for a disproportionate share of the country's burned area. In South Sumatra, more than 1,700 hotspots were detected in a single day over the weekend, reducing visibility to as little as 10 metres in some areas as smoke blanketed the province.

Palembang, the South Sumatran capital and one of Indonesia's largest urban centres, was photographed shrouded in haze, with residents walking across the Ampera Bridge barely visible through the smoke.

The cross-border nature of the crisis has put Indonesia's relationship with its neighbours under strain. Smoke from Kalimantan crossed into Sarawak, pushing air quality to "very unhealthy" levels in at least one district and forcing nearly 600 schools to close, affecting about 200,000 students.

Singapore's Government said its haze task force was ready to implement action plans if air quality in the city-state deteriorated, a standard precaution during severe Indonesian fire seasons. The ASEAN Specialised Meteorological Centre has been monitoring haze distribution and wind patterns across the southern ASEAN region throughout the crisis.

The fires are a recurring feature of Indonesia's dry season, driven by a combination of dry conditions, the vulnerability of peat soils to combustion once they dry out, and the enduring economic incentive for plantation operators and smallholders to clear land by burning. The method is cheaper and faster than mechanical clearing.

Peatland fires are particularly significant from a climate perspective. When deep peat layers catch fire, they can release carbon stored over thousands of years, making Indonesia one of the world's largest per-capita greenhouse gas emitters during severe fire seasons.

Madani Berkelanjutan estimated that about 22,200ha of land burned in 2026 was within key biodiversity areas, including parts of Bromo Tengger Semeru National Park in East Java. Fires there burned through dry grassland, native vegetation and protected edelweiss flowers, prompting the park to close to visitors.

Indonesia's Government has repeatedly pledged zero tolerance for deliberate land burning, but enforcement has been inconsistent across administrations. The 72 arrests represent one of the more aggressive law enforcement responses in recent memory.

However, Indonesian environmental groups have noted that previous crackdowns have rarely reached the corporate level, where the financial decisions creating the incentive to burn are typically made. Whether the investigation expands to plantation companies, as police have suggested, or ends with individual land clearers will be an important test of whether the enforcement approach has genuinely changed.

Originally published on HNGN