Tep Vanny, one of the country’s most prominent rights activists, was sentenced to two and a half years in prison…over charges related to a protest outside Prime Minister Hun Sen’s Phnom Penh mansion in 2013.

The decision is the latest in what is widely seen as a government offensive against critics, from activists and human rights defenders to political analysts and opposition officials. Ms. Vanny is among at least 25 political prisoners in the country, according to rights group Licadho…

Ms. Vanny was also ordered to compensate two state security guards, Hor Hoeun and Uk Rotana, 4 million riel (about $1,000) and 5 million riel (about $1,250) in compensation, respectively.

The activist claims that it was the security guards who attacked the protesters during the demonstration, in which 30 residents of the capital’s eviction-hit Boeng Kak neighborhood attempted to deliver a petition seeking the release of fellow activist Yorm Bopha…