Four people have been killed while battling wildfires in Indonesia's East Java province, as the country struggles with its worst forest fires in more than a decade.
The deaths come amid months of blazes that have spread toxic haze across Southeast Asia, worsening air quality, disrupting schools and prompting neighbouring governments to consider further action.
Indonesia's Forestry Ministry said Friday that the four victims were caught in flames Thursday while fighting a fire in Bromo Tengger Semeru National Park.
Two others sustained serious burns and are receiving medical treatment.
The ministry warned that firefighting operations carry significant risks, stressing the importance of monitoring wind conditions, tracking fire movements and maintaining evacuation routes.
Satellite monitoring identified 799 high-confidence hotspots nationwide as of Thursday night, an increase of 427 from the previous day.
Of those, 615 were recorded across six priority provinces.
Authorities cautioned that hotspots do not necessarily represent individual fires, as a single blaze can produce multiple satellite detections.
Sumatra and Borneo remain the worst-affected islands, with smoke spreading into neighbouring countries.
Singapore recorded an air quality index reading of 251 early Friday, classified as very unhealthy by monitoring company IQAir.
Singapore topped the company's live ranking of the world's most polluted major cities, followed by Kuala Lumpur, while Jakarta ranked sixth.
Singaporean Prime Minister Lawrence Wong warned that authorities could pursue companies responsible for transboundary pollution under legislation introduced in 2014.
However, legal experts noted that investigations depend heavily on international cooperation and access to detailed land and fire maps.
Meanwhile, Indonesian President Prabowo Subianto has approved accepting assistance from neighbouring countries, according to Foreign Minister Arrmanatha Nasir.
Malaysia previously offered three helicopters, an aircraft and 52 personnel, although no follow-up has been reported.
Singapore has also expressed readiness to assist.
The worsening haze has contributed to respiratory complaints affecting hundreds of thousands of people and forced school closures in Malaysia and East Timor, underscoring the expanding regional consequences of Indonesia's prolonged fire crisis.