A court in Rwanda has fined a man $900 (£746) after he pleaded guilty to involuntary manslaughter over the death of a journalist who was critical of the government.

John Williams Ntwali was killed last month when a speeding vehicle hit the motorcycle on which he was a passenger.

The authorities said it was a traffic accident.

Rights groups called for an independent investigation, describing his death as suspicious.

Human Rights Watch said Mr Ntwali had been regularly threatened and attacked in pro-government media for his investigative reporting.

The trial was not open to the public but some journalists were invited to witness the reading of the verdict.