A member of the public in the court denounced the outcome as "a parody of justice"
A court in Angola on Monday jailed 17 youth activists, including a well-known rapper, for rebellion against President Jose Eduardo dos Santos.
The verdicts and sentences, ranging from 2.0 to 8.5 years in prison, were handed down at the end of a lengthy trial in Luanda amid complaints from the Angolan opposition that the process proved the existence of ingrained political repression.
Rapper Luaty Beirao, who went on hunger strike for over a month last year to protest his detention, was given a five-and-a-half year sentence for "rebellion against the president of the republic, criminal association and falsifying documents".
Fellow activist Domingos da Cruz, who was identified by the judge as the "leader" of the group, was handed eight-and-a-half years for planning a coup and for criminal association.
The defendants remained calm as the sentences were read out before being taken away to jail at the judge's orders.
However a member of the public in the court denounced the outcome as "a parody of justice" and was arrested on the spot.
Outside the courtroom 30 protesters yelled "free the youths, arrest dictator Jose Eduardo dos Santos".
The activists insist they are peaceful campaigners for the departure of dos Santos, who has ruled the former Portuguese colony since 1979 and is Africa's second longest-serving leader. They were arrested in June and have always denied the charges against them.
Michel Francisco, a lawyer representing 10 of the accused, said he would appeal the convictions.
"Justice has not been done in a transparent way because things have been politicised and the judge only obeyed higher orders coming from the president of the republic," he told reporters.
Rights groups say activists in Angola, Africa's second-largest oil producer, are being increasingly targeted by dos Santos' government.
Amnesty International said the activists should not have been arrested in the first place and described their detention as a "travesty of justice".
Human Rights Watch denounced the verdict as "outrageous and ridiculous".
"Angola has once again failed to show that it is committed to respecting human rights values which are protected by their own constitution," HRW's spokeswoman Zenaida Machado told AFP.
"If a judge says that reading a book and meeting to discuss or plan a peaceful protest is a crime, than what would be, in Angola, considered freedom of assembly and protest?" she asked.
During the trial, da Cruz was made to read out, in its entirety. a 183-page book he had written, entitled "Tools to destroy a dictator and avoid a new dictator," which his co-accused were said to be reading when they were arrested.
Only 14 of the defendants were present in court on Monday to hear their fate. Nuno Dala has been on hunger strike since March 10 and has been hospitalised. Two others who had attempted to enter the court carrying law books were refused entry.
On March 11, dos Santos, 73, said he would step down in 2018 but the announcement was received with scepticism following two similar pledges in the past. His current mandate ends at the end of next year.
International media were banned from the court during the trial.