Seventeen Angolans accused of planning a rebellion and coup have gone on trial in Luanda, in a case that rights groups say shows the government's intolerance of dissent.
Authorities arrested the young activists in June after they met at a book shop to discuss a book called "From Dictatorship to Democracy."
Their defense lawyer told the court Monday that charges should be dropped because they broke no laws and have a constitutional right to freedom of speech.
Amnesty International calls the trial a "travesty of justice," while Zenaida Machado, a researcher for Human Rights Watch in Angola and Mozambique, says it is a moment for Angola's judiciary to show it will respect fair trial standards.
"Angolan judges should show independence and not permit this trial to be used as an instrument to silence the government's critics," she said.
VOA's Portuguese-to-Africa service reports the trial is expected to last until Friday.
Angolan President Jose Eduardo dos Santos has been in power for 36 years, longer than all but one other leader on the African continent.
Rights groups say his government has used arbitrary detentions, torture and extrajudicial killings to suppress critics and stay in power.