Outbreaks of smog-belching forest fires in 2019 caused Malaysia to say it would pressure Indonesia to combat the annual problem, which is often caused by blazes lit to clear agricultural land.
Malaysia’s Department of Environment director general Wan Abdul Latiff Wan Jaffar said the fires were worsening air pollution on the country’s west coast and in Sarawak on the Malaysian part of Borneo island.
“Overall air quality in the country shows deterioration,” he said in a statement issued on Friday.
“Forest fires that occur in the southern part of Sumatra and the central and southern parts of Kalimantan (Borneo), Indonesia have caused haze to cross borders,” he said.
The statement said satellite imagery showed 52 forest fire “hotspots” in Sumatra and 264 in Borneo, according to a report from the Singapore-based Asean Specialised Meteorological Centre (ASMC), which tracks haze affecting Southeast Asia.
Twelve areas in Peninsular Malaysia recorded unhealthy Air Pollutant Index levels above 100 as of 8pm local time on Friday, with the highest of 155 registered in an area of Kuala Lumpur, it added.
Indonesia’s environment minister hit back at the claims.
“The fact is that there is no transboundary haze,” Siti Nurbaya Bakar said on Saturday, sharing ASMC images she said showed only haze in Sumatra and Borneo.
“They (Malaysia) refer to hotspot data? Don’t they know the difference between hotspots and firespots? If (you) don’t know exactly, don’t talk carelessly.”
She said Jakarta would review and punish companies if the government found wildfires in their concession areas.
Firefighters on the western Indonesian island of Sumatra battled large peatland fires this month that covered Palembang, a city of nearly two million people, in haze for weeks.
The Indonesian fires take place every year during the dry season but these are the worst since 2019, when they forced nearly 2,500 schools to close across Malaysia.
Fires in 2015 were also among the deadliest on record, cloaking Southeast Asia in toxic smoke for weeks and causing many people to become ill, schools to close, and flights to be cancelled.
The vast majority of Indonesia’s forest fires take place on Sumatra and Borneo, which is divided between Indonesia, Malaysia and Brunei.
Indonesia and Malaysia have both carried out “cloud-seeding”, which uses chemicals in a bid to induce rain, in previous attempts to battle the fires.
Additional reporting by Bloomberg News