Filed at 11:33 a.m. ET

KIGALI, Rwanda (Reuters) - Rwandans hungry for justice demanded Monday tougher efforts to track down and punish killers who carried out the 1994 genocide, saying there could be no reconciliation while suspects were still at large.

Delivering justice to genocide victims has proved a tough challenge for Rwanda, burdened by more than 80,000 prisoners accused of crimes during the massacres 10 years ago and the knowledge that many top suspects are still hiding abroad.

``If there's no justice, there can be no reconciliation. We need to know the truth,'' Antoine Mugesera, former head of the genocide survivors group Ibuka, told a conference marking the 10th anniversary of the genocide.

``There were more than a million victims, that means there's an even greater number of people who are guilty,'' he said, referring to the way many killings were carried out by mobs hacking or clubbing victims to death.

``That's the challenge; to bring all these people to justice,'' he told Reuters on the sidelines of the second day of a three-day conference to draw lessons from the genocide.

Participants discuss justice and reconciliation Monday ahead of a memorial ceremony Wednesday to bury some of the most recently discovered victims in a tomb housing the remains of an estimated 250,000 people killed in the capital Kigali.

OVERCROWDED JAILS

The genocide began after a plane carrying the Rwandan and Burundian presidents was shot down on April 6, 1994, triggering a massacre of Tutsis and moderate Hutus by extremists from the politically-dominant Hutu majority.

The African Union (AU) association of African nations,, planning a multinational force to intervene across the continent in civil wars, said it was better prepared to ensure such genocide would not be repeated.

``The effort of the Peace and Security Council of the AU will be assisted by early warning systems which will inform the Council on what is taking place in every corner of the continent,'' Julia Dolly Joiner, commissioner for AU political affairs told an Addis Ababa news conference.

One of the most pressing issues is how to deal with the thousands of suspects held in overcrowded Rwandan jails, whose trials for their suspected role as rank-and-file killers will take decades to resolve using normal courts.

Rwanda has introduced a system of village courts known as Gacaca to speed up the process, training local judges and asking neighbors to act as informal juries in trials for people who may have been their friends or even relatives.

Progress in finding more senior suspects accused of masterminding the killings has also been fraught.

The U.N. International Criminal Tribunal for Rwanda has arrested 66 of the 81 people indicted for genocide-related crimes, but has made only 18 convictions in 10 years, hardly satisfying Rwanda, which says some 300 ringleaders live abroad.

The United States, criticized for not doing more to stop the killings, has offered multi-million dollar rewards for suspects.

Pierre-Richard Prosper, U.S. ambassador at large for war crimes issues, called for more cooperation from African countries in international attempts to arrest fugitive suspects.

``We are saying to everyone 'It's been 10 years, please look and see what your country can do to solve the problem','' he said. ``While these suspects remain out there at large, it continues to keep the aftermath of the genocide alive.''

Asked which countries he especially wanted to help in the hunt for suspects, he mentioned the Democratic Republic of Congo and the Congo Republic, where many former Hutu militants took refuge after participating in the genocide.