The trial of security forces and army officers accused of the killing of 353 refugees in 1999 in the Republic of Congo has opened.
Only 14 of the 16 accused were present at the hearing postponed on Tuesday because of procedural problems.
The so-called Beach case, named after the port of the Congolese capital Brazzaville, relates to refugees returning from neighbouring DR Congo.
Relatives and human rights groups say the victims were tortured and executed.
Hundreds of family members, relatives of the accused and onlookers who wanted to attend the trial were forced to remain outside the packed courtroom, with police blocking access, reports the AFP news agency.
The accused face charges of genocide, crimes against humanity, war crimes and murder over the disappearance of President Denis Sasso Nguesso's former opponents.
They were arrested as they returned home to the capital's port from the Democratic Republic of Congo, which lies on the other side of the river Congo, to the smaller, former French colony.
They were held before they disappeared on suspicion of alleged ties with a militia hostile to the government, then still in conflict with rebels on the outskirts of Brazzaville.