Some 5,000 people were slaughtered at the Nyanza site for Tuesday's commemoration. That massacre came four days after a deadly attack on Belgian United Nations peacekeepers that led the troops to withdraw -- which Kagame said made the outside world "guilty."

The April 7, 1994 attack by Rwandan forces claimed the lives of 10 Belgian troops.

"We are not like those who abandoned people they had come to protect. They left them to be murdered. Aren't they guilty?" Kagame said of those who commanded the UN presence.

"I think it is also cowardice. They left even before any shot was fired. We are not cowards. They (the international community) are part of that history and the root causes of the genocide," Kagame added.

The secretary general of the country's genocide survivors group, Ibuka, said the site in Nyanza marked the "failure of the international community."

"It is the failure of humanity as a whole," said Benoit Kaboyi.

Venuste Karasira, who survived the attack in Nyanza, said they were "certain their (Belgian troops) departure sealed our fate."

"The Interahamwe (Hutu militia) surrounded us. They opened fire and threw grenades. We were all lying in pools of blood. I was among dead bodies, covered with blood and pieces of flesh. They thought I was dead," Karasira recounted.

Rwanda declared a week of national mourning and Kagame placed a wreath at the hill site in Nyanza and lit a torch in memory of the victims, mainly minority Tutsis and moderate Hutus killed across the small central African country by extremist Hutu militia during the 100-day wanton slaughter.

Kagame also led a symbolic burial of a victim's remains with the crowd marching past a monument to pay homage to all the genocide's victims.

The ceremony was marked with prayers and choruses by a children's choir who sang of hope.

"As we remember, life must go on. We must continue to build a better future," said Kagame. "We have achieved very significant and tremendous progress.

"Our future, no one can decide it for us. We have to continue to move and look forward," he added.

Kigali has repeatedly accused the world of not doing enough to hunt down genocide perpetrators still at large -- and some nations, notably France, of failing to acknowledge their role in allowing the killings.

Hundreds of suspects sought over their involvement in the killings are living in countries including Belgium, Canada, the Democratic Republic of Congo, France and Kenya.

Kagame, whose then Rwandan Patriotic Front rebel group took over in the aftermath of the genocide, has ruled the country since bringing an end to the massacre.

His Tutsi-led government has been criticized in recent years for keeping ethnic animosity alive even after the genocide by labelling its political foes "divisionists."

Rwanda's criminal investigations department has identified over 2,000 cases of murder, torture and intimidation of genocide survivors recorded since 2007.

Aimable Twahirwa

AFP/Expatica