An official Bosnian Serb investigation into the Srebrenica events of July 1995 has found that several thousand Muslims were murdered by local Serb forces.
More than 7,000 are thought to have been killed at Srebrenica
It is the first time the Bosnian Serb authorities have admitted the killings which The Hague war crimes tribunal has declared an act of genocide.
The Bosnian Serb commission reported "grave" violations of human rights and an attempt to conceal evidence.
It also revealed the discovery of 32 previously unknown mass grave sites.
Despite the findings, the BBC's Nick Hawton reports, critics argue that real progress will only occur when the Bosnian Serb authorities carry out their first arrest of a suspected war criminal.
This is something they have failed to do since the end of the civil war eight and a half years ago.
According to the report:
- Bosnian Serb forces planned a three-stage operation: the attack on the town, the separation of women and children and the execution of the men;
military and police units, as well as special units of the interior ministry, took part in the murders;
four new graves are original sites while the other 28 are sites where bodies were reburied to hide traces of the massacre;
the commission has data on 7,779 people missing in Srebrenica and has so far identified 1,332 of them.
The seven-member commission, which includes one international and one Muslim member, was set up amid pressure from Bosnia's internationally-run human rights chamber, which ordered the Serb authorities to investigate what happened.
"This report will have a historic character," said Milan Bogdanic, its head.
"We have reached historic perceptions and we will have to face ourselves."
Our correspondent says that this is the furthest any Bosnian Serb authorities have gone in admitting their involvement in events around Srebrenica.
The chief international envoy to Bosnia, Lord Ashdown, has said this could indicate a new willingness on their part to face up to their responsibilities.
The International Criminal Tribunal for the former Yugoslavia has to date indicted 14 suspects over the massacre but only four have been sentenced.