A court in south-central Vietnam's coastal Khanh Hoa province convicted two online activists of conducting propaganda against the state on Tuesday, handing one a three-year term and sentencing the other to two years in a closed trial, sources said. Nguyen Huu Quoc Duy, 31, was arrested by provincial police on Nov. 21, 2015, after authorities accused him and his cousin, Nguyen Huu Thien An, of using Duy's Facebook page to incite others to oppose the government. He was sentenced on Aug. 23 to three years in prison by a court in Khanh Hoa's Nha Trang city under Article 88 of Vietnam's penal code, sources said. "This is an unjust sentence," an activist from Saigon who went to Nha Trang to attend the trial told RFA's Vietnamese Service on Tuesday. "Duy only blacked out his Facebook page and wrote "Forty years have passed, DMCS'[a four-letter abbreviation for an obscenity attacking Vietnam's ruling communists]," RFA's source said, speaking on condition of anonymity. "There is no law governing these four letters, and now they have charged and convicted him under Article 88," he said. "I think they just arrest anyone they want to." Article 88 of Vietnam's criminal code carries a maximum penalty of 20 years' imprisonment for the ill-defined offense of spreading "anti-state propaganda." Human rights groups claim Article 88 is used to imprison peaceful activists in the one-party communist nation. Closed trial Tuesday's trial, in which Duy's cousin received a two-year term, was closed to the public, with the defendants' mothers also barred from entry, sources said. "No one could get in," one activist in Nha Trang told RFA. "[The police] have been blocking all access to the courthouse since 9:00 a.m. We could only meet in a local caf_, but security people were everywhere." "Some activists coming from Saigon were stopped at Cam Ranh," the activist said. Duy's mother Nguyen Thi Nay had asked two lawyers before the trial began to represent her son in court, but court officials had not replied to the attorneys' application to attend, one of the two lawyers said. "We have now heard that the trial took place today, Aug. 23," the lawyer, Le Kha Thanh, told RFA. "We don't know what to do now, because neither of us can participate."