The government plans to sue three companies and an individual for allegedly igniting fires in Sumatra's forests, and has seized 6,300 hectares of land the suspects are said to have cleared by burning.

State Minister for the Environment Rachmat Witoelar said Wednesday the suspects started fires that have destroyed thousands of hectares of peatland and forests in Sumatra and Kalimantan. The fires produced toxic haze that blanketed a significant portion of the islands and spilled over to neighboring countries.

"We suspect that more than 20 companies, some of them state-owned companies, have been involved in forest burning," he told reporters at his office. He said he would disclose their names on Friday, after his officials completed their investigation reports.

The numbers were far lower than data released by the Indonesian Forum for the Environment (Walhi), which has identified 106 logging and plantation companies it believes are responsible for burning forests on their concessions.

Walhi handed the names of the companies to the police for investigation Wednesday.

Rachmat's deputy for environmental law enforcement, Hoetomo, said his officials have gathered sufficient evidence to sue only four of the alleged perpetrators.

"Three are companies and one is an individual, all of them in Riau," he said.

He said the 6,300 hectares of burned land that were seized will be used as material evidence for court proceedings.

He said the land was confiscated not only to prevent companies or landowners from profiting from it, but also to gather evidence to show that the fires were started deliberately.

"Our experts are working in the seized areas to analyze what substances were used to set the fires, and where they started," he said.

Meanwhile, Coordinating Minister for the People's Welfare Aburizal Bakrie claimed that the government had extinguished most of the fires in Sumatra through induced rain and water bombings.

"Today, almost 80 percent of the fire hot spots have been extinguished," Bakrie said, as quoted by Antara.

He said the government would keep on battling the fires until the choking haze disappears by inducing rain, rather than water bombing, as the latter required 10 to 14 days of preparation.

"State Minister for Research and Technology Kusmayanto Kadiman is overseeing the artificial rain. Hopefully, within one or two days the rain will reduce the smoke even more," he said.

Forestry Ministry director for forest protection Noor Hidayat fears continuing fires and rampant illegal logging will so degrade the country's remaining 120 million hectares of forests, of which about half are already damaged, that only 10 percent will remain by 2020.