Three Rwandan media executives have been found guilty of inciting violence during the genocide of 1994.
Jean-Bosco Barayagwiza boycotted the trial
Two worked for a radio station which broadcast lists of people to be killed and revealed where they could be found. The three were given long jail terms.
"Without a firearm, machete or any physical weapon, you caused the deaths of thousands of innocent civilians," said the international court judge.
About 800,000 Tutsis and moderate Hutus were slaughtered in just 100 days.
Ferdinand Nahimana, who was sentenced to life in prison, and Jean-Bosco Barayagwiza, who got 35 years, helped set up a private radio station - Radio Television Libres des Mille Collines (RTLM) - which urged Hutus to "exterminate the cockroaches".
"Nahimana chose a path of genocide and betrayed the trust placed in him as an intellectual and a leader," said Judge Navanathem Pillay.
Hassan Ngeze, who was sentenced to life, was the editor of an extremist magazine called Kangura.
Judge Pillay told him he had "poisoned the minds of your readers" against Tutsis.
They were all found guilty of genocide, incitement to commit genocide and crimes against humanity by the International Criminal Tribunal for Rwanda, based in the Tanzanian town of Arusha.
The BBC East Africa correspondent, Christian Fraser, says the power of the radio in a poor country with low literacy rates cannot be overstated.
He says that during the genocide, those manning the roadblocks where Tutsis were stopped and slaughtered, were often listening to radios.
Barayagwiza boycotted the trial, saying it would not be fair.
Defence lawyers for the others had argued that the trial was an attack on free speech and the freedom of the press.
Nahimana and Barayagwiza were arrested in Cameroon in March 1996 and Mr Ngeze in Kenya in July 1997.
Barayagwiza's sentence was reduced to 27 years because of the time he has already served.
The trial began in 2000.
On Monday, a former mayor was sentenced to life for his role in the genocide.
In nine years, the tribunal has convicted 16 people and acquitted one, prompting criticism from the Rwandan Government for the slow pace of its justice.
A new chief prosecutor has been named, along with extra judges and two new trials started last month.
Reuters news agency reports that more than 40 other suspects are in custody.