The Phnom Penh Municipal Court on Monday convicted Mam Sonando, owner of an independent Beehive radio station, of four counts related to a secessionist movement and sentenced him to 20 years in jail and fined $2,500, according to a verdict.

The verdict, read by Presiding Judge Chang Sinat, said that Mam Sonando, 70, who is also president of the Association of Democrats, was charged with fomenting ideas against public government officials, fomenting illegal insurrection when the authority was undertaking public work, inciting people to hold illegal arms, and opposing the legal authority as stipulated in a number of sections of the criminal law.

The charges were made after he masterminded a plot to establish an autonomous region in eastern Kratie province in May. At that time, there was a violent clash between the government forces and illegal land holders. As a result, a 14-year-old girl was shot dead by government forces.

Mam Sonando was arrested on July 15 at his house in Phnom Penh.

The court also convicted in absentia of his accomplices including Bun Ratha to 30 years in jail, Kong Tong to 15 years in jail, and Bun Chhorn to 15 years, and an arrest warrant was also issued for the three fugitives.

Outside the court on Monday, hundreds of Mam Sonando's supporters protested, holding posters calling for his release and chanting about injustice.

Mam Sonando told reporters after the verdict release that "the verdict is unjust".