Rwanda's main sports stadium was the site of national mourning on Monday. Thousands of people flocked to the arena in Kigali to commemorate the loss of nearly 1,000,000 lives to a genocide that swept over the African country 20 years ago.

"Today Rwanda remembers those who lost their lives in the genocide and gives comfort to those who survived," Rwandan President Paul Kagame told the crowd.

"No country, in Africa or anywhere else, ever needs to become another Rwanda," Kagame added.

Ethnic violence between Rwanda's Hutu and Tutsi populations escalated in 1994 to mass killings, recognized too late by the international community as genocide. The roughly 100 days of ethnic cleansing began on April 7, 1994, the day following the assassination of President Jevenal Habyarimana, a Hutu. His death prompted the bloodshed that saw over 800,000 Tutsis perish at the hands of the country's Hutu population.

The United Nations was criticized for inaction at the time, a mistake which can only be amended by preventing future genocides from happening, UN Secretary General Ban Ki-moon said on Monday.

"Many United Nations personnel and others showed remarkable bravery. But we could have done much more. We should have done much more. In Rwanda, troops were withdrawn when they were most needed," Ban said in Kigali.

At the time, the UN peacekeeping force was reduced from roughly 2,500 personnel to just over 250.

"The shame still clings, a generation after the events," Ban said, calling the Rwandan genocide "one of the darkest chapters in human history."

Officials also marked the day by laying a wreath at Kigali's Genocide Memorial Center. Meanwhile, the "Flame of Hope" which has been travelling the country for the past three months arrived in the capital. President Kagame and UN Secretary General Ban lit a separate flame which will now burn for the next 100 days.

Diplomatic spat overshadows day

French officials were omitted from the list of invitees to Kigali on Monday following renewed accusations by Rwandan leadership of their complicity with Hutus in 1994.

Michel Flesch, France's ambassador to Rwanda said on Monday that his invitation had been revoked. The French government had selected him as a second choice after deciding against sending a ministerial delegation over the uproar.

On Sunday, Rwandan Foreign Minister Louis Mushikiwabo added to the accusations against France by calling on its leadership to face up to the "difficult truth" of the actions of President Francois Mitterand's government at the time.

"For our two countries to really start getting along, we will have to face the truth. The truth is difficult, the truth of being close to anybody who is associated with genocide understandably is a very difficult truth to accept," Foreign Minister Mushikiwabo said.

The French presidency refrained from commenting on the spat in a statement it issued on Monday afternoon.

"France joins the Rwandan people to honor the memories of all victims of the genocide," the statement said.

However, the former commander of the French military mission in Rwanda, General Jean-Claude Lafourcade, rejected the allegations during an interview with RTL radio.

"I find Mr. Kagame’s accusations unfounded and unfair – they completely tarnish this day of commemoration for a global human tragedy," Lafourcade, adding French soldiers did not arrive in the country until June, after the genocide had taken place.

kms/dr (AP, AFP, dpa)