GENEVA (Reuters) - The United Nations called on Vietnam on Friday to release a prominent dissident who was jailed for nine years this week, according to her lawyer, after a one-day trial for spreading propaganda against the state.


The severity of the sentence passed on blogger Tran Thi Nga and the conduct of her trial did not meet the standards of due process and provoked "serious concerns", U.N. human rights spokeswoman Liz Throssell told a news briefing in Geneva.


Tran, who was also given five years probation, was kept incommunicado in detention for about six months from her arrest in January until a few days before the trial, and not given adequate time to prepare her defence, Throssell said.


Her sentencing came a month after another prominent blogger, Nguyen Ngoc Nhu Quynh, known as Mother Mushroom, was jailed for 10 years "following similarly flawed judicial proceedings", she said.


In the last six months, at least seven other activists have been arrested and face prosecution, she said. Several dozen are currently detained and four have been deported or sent into exile in France or the United States since 2014, she added.


"We urge the Vietnamese authorities to immediately release all those detained in connection with their exercise of their rights to freedom of expression," Throssell said.

(Reporting by Stephanie Nebehay; Editing by Richard Balmforth)