Indonesia haze spreads across region as firefighters battle wildfires

Indonesian authorities are focusing their firefighting efforts on six provinces – including Jambi, South Sumatra, West Kalimantan, Central Kalimantan, South Kalimantan, and Riau – that have vast areas of peatland and are vulnerable to fire during the annual dry season.

A resident in Central Kalimantan told BBC Indonesian he had been experiencing wildfires "for more than a month".

"The smoke has become quite thick. When we step outside, our eyes start to sting. The smell of the smoke is also quite strong," says Darwin Romy, an indigenous Dayak who lives in the province's largest city Palangka Raya.

"The flames have already gotten close to residential areas ... The problem is that water is starting to run dry here [for firefighting]," he says.

The mayor of the city of Pontianak in West Kalimantan said students would attend lessons online for as long as the fires continued.

"We have started to feel it, especially at night and in the morning, as haze has already blanketed the city of Pontianak," the mayor, Edi Rusdi Kamtono, said on Monday, as reported by AFP news agency.

In addition to the six worst-hit provinces, a fire burned for nearly a week at Mount Bromo National Park in East Java, razing around 550 hectares of the park, before it was put out on Monday.

Authorities have also warned of new hotspots near the caldera of Mount Bromo, which is an active volcano and a major tourist attraction. It has been closed to visitors since 8 August.

The official cause of the fire is still under investigation, but local authorities say it may have been due to carelessness.

"A person lit a fire, then put it out, but the fire was not fully extinguished," Gatot Soebroto, who leads the local disaster mitigation agency, told reporters on Monday.

The haze has spread to neighbouring Malaysia. The small town of Serian in Sarawak logged the state's highest Air Pollutant Index (API) reading of 195 on Wednesday morning.

An API reading of 101 to 200 is deemed "unhealthy", a reading of 201 to 300 is deemed "very unhealthy", while anything above 301 is considered "hazardous".

At least nine areas across Sarawak recorded unhealthy API readings as of Wednesday, according to Malaysian media reports.

With reporting by Lesthia Kertopati and Farida Susanty in Jakarta

Reporting from BBC News contributed to this story.