Fires have broken out in four provinces — South Sumatra, Riau, West Kalimantan and Central Kalimantan — prompting them to declare “alert emergency” status, one notch below the most severe warning.
Hundreds of hectares of land have been destroyed over the past week and the government is stepping up efforts to contain the fires.
The blazes are frequently deliberately set by farmers using fire to clear land for cultivation.
“We are now preparing planes for cloud seeding and helicopters for water bombing,” said disaster mitigation agency Sutopo Purwo Nugroho.
The agency will deploy soldiers, police, firefighters and volunteers to combat the fires, officials said.
The annual forest fires on Sumatra island and the Indonesian part of Borneo island typically occur during the months-long dry season which usually begins in January.
In 2015 massive forest fires in Indonesia destroyed some two million hectares and sparked a massive haze outbreak over Singapore and Malaysia, leading to diplomatic frictions.
A US academic study estimated that the crisis may have led to more than 100,000 premature deaths.
