Indonesian satellites yesterday morning picked up 282 hot spots - believed to be the highest number across the country this year - as the dry season continues.
The worst hit province was West Kalimantan, where more than half of the hot spots were detected, said National Disaster Management Agency (BNPB) spokesman Sutopo Purwo Nugroho, as he released the figures yesterday evening.
Five districts in the province - Kubu Raya, Ketapang, Sekadau, Melawi and Bengkayang - have declared a state of emergency to enable the local authorities to access central government support, including military assistance, to put out the fires.
Dr Sutopo also expressed concern that although 150 hot spots were detected across West Kalimantan, the number of fires there may be higher. "Land and forest fires in West Kalimantan continue despite our continued efforts to suppress them," he said.
He warned that the number of hot spots is probably higher as the satellites may not have passed over all the forest and land areas where fires could be burning.
Other areas in Indonesia were also hit by forest fires, albeit not as badly as in 2015, when the burning of forest and peatland in Kalimantan and Sumatra produced a transboundary haze that blanketed the region and led to record air pollution levels for months.
Aside from those in West Kalimantan, the hot spots were spread across other provinces such as South Sumatra (23), South Sulawesi (18), Riau (16) and East Nusa Tenggara (12).
Dr Sutopo said the hot spots were spotted on private plantation land, community-owned land and in national parks, in hard-to-reach locations. "The areas burned are generally areas that are difficult to access and away from settlements, that is why (the fires) are difficult to extinguish," he said.
As of last Saturday, 18 helicopters have been deployed for firefighting operations in Riau, Jambi, South Sumatra, West Kalimantan and South Kalimantan. All five provinces are currently in a state of emergency.
Indonesia's Environment and Forestry Minister Siti Nurbaya Bakar said last week that helicopters will deployed to put out fires over areas where there is limited road access.
"If land access is difficult or shut down for a long time, then we will use water-bombings," she said.
The dry season in Indonesia has been forecast to end next month at the earliest.