A Cambodian court on Thursday began hearing the cases of nearly 130 government critics and opponents charged with treason for taking part in nonviolent political activities over the past three years, in what one of them called a sham trial.

Only 33 defendants attended Thursday's session at the Phnom Penh Municipal Court, with some believed to be overseas. Most are former members or supporters of the disbanded Cambodia National Rescue Party. As the sole opposition party in Parliament, it had been expected to present a strong challenge to Prime Minister Hun Sen's Cambodian People's Party in the 2018 general election.