(Reuters) - A Vietnamese student activist was jailed for six years plus four years of probation by a local court on Wednesday for conducting propaganda against the state, his lawyer said. Despite sweeping reforms to its economy and growing openness to social change, including gay, lesbian and transgender rights, Vietnam s sole Communist Party retains tight media censorship and does not tolerate criticism. Phan Kim Khanh, 24, is a student studying international relations and the eldest child of a Catholic farming family in a remote area north of capital Hanoi. He had written blogs criticizing the government before he was arrested earlier this year.  The proof used in court against Khanh was vague,  lawyer Ha Huy Son told Reuters, adding he was not certain if Khanh wants to appeal. Human Rights Watch on Tuesday called on Vietnam to drop all charges and release Khanh.  The bogus crime of conducting propaganda against the state is designed to silence peaceful critics of the Vietnamese authorities,  said Brad Adams, Human Rights Watch s Asia director.   Vietnam ought to get rid of these laws and stop persecuting students and ordinary people for just talking about the country s problems on the internet.  