Seventeen people have been arrested since late January for sharing information about the coronavirus in Cambodia, including four members or supporters of the dissolved opposition Cambodia National Rescue Party (CNRP), New York-based Human Rights Watch said.
They were charged with penal code violations including incitement, conspiracy, and spreading false information, the group said.
The arrests included a 14-year-old girl who expressed fears on social media about rumours of coronavirus cases at her school and in her province, Human Rights Watch said. Twelve were released from detention after signing pledges not to spread "fake news" and to apologise, the group said.
"The Cambodian government is misusing the COVID-19 outbreak to lock up opposition activists and others expressing concern about the virus and the government's response," said Phil Robertson, the group's deputy Asia director, referring to the disease associated with the virus.
"It's truly frightening that during a national crisis, the Cambodian government seems more interested in silencing online critics than undertaking a massive COVID-19 public information campaign," Robertson said.