Indonesian police have named seven companies and 133 individuals suspected of causing forest fires that are spreading choking smoke and polluted air across parts of western Indonesia and neighboring countries.

National Police spokesman Col. Suharsono says Thursday that 27 more companies and 85 people are still under investigation.

Suspects from companies include general managers and operational managers. Suharsono said some of the suspects have been arrested.

Many forest fires were set illegally to clear land for farming. Indonesia is mobilizing thousands of soldiers, police, firefighters and volunteers to help extinguish fires and is sending 21 aircraft to conduct cloud seeding and water dropping.

Peat-rich Riau province declared an emergency Monday because of the bad air quality, which was threatening people's health and disrupting flights and other activities.