Rwanda’s president said the country had become “a family once again”, while marking the 25th anniversary of the genocide that killed 800,000 people.
Paul Kagame, who led a rebel force that ended the slaughter, lit a remembrance flame in the capital Kigali.
Rwandans will mourn for 100 days, the time it took in 1994 for about a tenth of the country to be massacred.
Most of those who died were minority Tutsis and moderate Hutus, killed by ethnic Hutu extremists.
“In 1994, there was no hope, only darkness,” Mr Kagame told a crowd gathered at the Kigali Genocide Memorial, where more than 250,000 victims are thought to be buried.
The commemoration activities began with a flame-lighting ceremony.
