JAKARTA • Indonesia's disaster mitigation agency (BNPB) has warned of an escalating threat of forest fires with the dry season expected to peak in coming months, while hot spots detected in the province of Aceh have already been causing choking smoke.

Fires had spread to around 64 hectares of fields and forests in Aceh, a northern province on the island of Sumatra, producing haze, and some residents had been taken to hospital due to breathing problem, the agency said yesterday.

"The peak of the dry season is predicted to be in August and September, so the threat of forest and field fires, and drought will escalate," Mr Sutopo Purwo Nugroho, a BNPB spokesman said in a statement.

The fires in Aceh started on July 18 and the authorities are still trying to extinguish them in some areas. Satellite images showed 170 hot spots across the country, including 35 in Aceh province on Sumatra island, 44 in East Nusa Tenggara and 21 in West Kalimantan, according to the National Disaster Management Authority.

The BNPB said on Twitter that affected areas also include other parts of Sumatra, Kalimantan on Borneo, Java and Sulawesi.

West Kalimantan Disaster Mitigation Agency head TTA Nyarong said the province's administration had anticipated the condition by preparing four helicopters for water bombing operations, and by activating disaster mitigation command posts in several disaster-prone areas.

Indonesia is regularly hit by forest fires, which can result in choking smoke blowing across to neighbouring countries like Singapore and Malaysia.

Indonesia suffered some its worst forest fires in 2015, mainly in the island of Sumatra and in Kalimantan, the Indonesian part of Borneo island.

The World Bank, citing government data, said that 2.6 million hectares of land in Indonesia burned between June and October 2015, causing US$16 billion (S$22 billion) of estimated economic damage.

Draining and conversion of peatland, often driven by oil-palm plantations, contributed to the intensity of haze from the fires.

The head of Indonesia's Peatland Restoration Agency told a conference in May there would be "no more haze going to the neighbours", as the authorities implemented new measures to fight the fires.

The Indonesian government has extended a moratorium on issuing new licences to land designed as forest and peatland for another two years, the presidential office said yesterday.

The move is partly aimed at protecting the ecosystem, restoring peatland after forest fires, and reducing emissions.

President Joko Widodo inked a presidential instruction on the extension of the moratorium.

"I instruct to continue moratorium on awarding a new licence for land designed as primary forest and peatland located in conservation forest, protected forest, and productive forest," the statement said.

The ban issued in 2011 has now been extended twice as environment groups and consumers, including Unilever and Nestle, push for production of palm oil that is certified as sustainable.

By November last year, the government had put more than 66 million hectares under the coverage of the moratorium.

REUTERS, BLOOMBERG, XINHUA, THE JAKARTA POST/ASIA NEWS NETWORK