Indonesia has arrested 185 people suspected of starting forest fires which has spread thick haze throughout Southeast Asia.
Forest fires are believed to have been started by plantation owners to help clear land for planting, with smog spreading to neighbouring Malaysia and Singapore.
National Police spokesman said investigations into 23 suspects have been handed over to prosectuors, while 45 others face trial later this month.
Nearly every year, Indonesian forest fires spread haze throughout Southeast Asia. In Malaysia, authorities in the capital Kuala Lumpur handed out masks to help protect people from inhaling toxins.
The arrests were made across six provinces and a state of emergency has been declared over the forest fires.
Police said the suspects could face a maximum of 10 years in prison under environmental laws.
The thick haze and poor visibility caused by the smoke has caused delays to flights in several airports in Indonesia and Malaysia, and forced authorities to shut schools in some parts of the two countries.
The Indonesian Disaster Mitigation Agency detected 2,153 hotspots across the country on Monday. It said 99 per cent of the hotspots were caused by deliberately set fires.
The agency said 44 helicopters had dropped more than 263 million litres (69.5 million gallons) of water and 164 tonnes of salt for cloud seeding as part of the firefighting efforts.