Rwanda is marking the 25th anniversary of the genocide in which 800,000 people - one tenth of its population - were killed in 100 days of slaughter with a week of commemoration activities and 100 days of national mourning.

Here are some facts about one of the darkest chapters in human history:

Rwanda Genocide anniversary

Mass grave containing the remains of over 250,000 Rwandans who were killed during the 1994 genocide at Kigali Genocide Memorial on 4th April, 2019. PICTURE: Thomson Reuters Foundation/Nita Bhalla

• On the night of 6th April, 1994, a plane carrying then Rwandan President Juvenal Habyarimana and his counterpart Cyprien Ntaryamira of Burundi - both Hutus - was shot down, killing everyone on board.

• Hutu extremists blamed the Rwandan Patriotic Front - a rebel group made of exiled Tutsis - and launched a campaign of slaughter against Tutsis. The RPF claim the plane was shot down by Hutus to provide an excuse for the genocide.

• Over the next 100 days, more than 800,000 Tutsis and moderate Hutus were slaughtered by Hutu extremists, led by the Rwandan army and a militia known as the Interahamwe.

• They set up road blocks across the country and went from house to house killing men, women and children. They used radio broadcasts to incite hatred against Tutsis and called on ordinary Hutus to identify and kill all Tutsis.

• Hutu leaders handed out "kill lists" to militias familiar with local communities so they could locate and murder Tutsis. Neighbours killed neighbours and Hutu husbands even murdered their Tutsi wives out of fear for their own lives.

• Many Tutsis fled to churches to seek sanctuary, but priests and nuns in some cases informed militias of sheltering Tutsis who then killed them, either by burning down the churches or slaughtering them with machetes.

• As many as 10,000 people were killed per day. Seventy per cent of the Tutsi population was wiped out, and more than 10 per cent of the total Rwandan population.

• Sexual violence was used as a weapon of war with up to 250,000 women and girls raped, resulting in thousands of births.

• Hutus also released AIDS patients from hospitals in order to form "rape squads" to infect Tutsi women. As a result, thousands of survivors and their children born from rape are infected with the HIV/AIDS virus.

• The genocide ended in July, 1994, as the RPF, backed by Uganda's army, seized more territory and took control of Rwanda.

• Fearing revenge attacks, about two million Hutus - both civilians and some of those involved in the genocide - fled to neighbouring countries such as the Democratic Republic of Congo, Tanzania and Burundi.

• Human rights groups say RPF fighters killed thousands of Hutu civilians as they took power. The RPF denies this.

• The International Criminal Tribunal for Rwanda was established in Tanzania in November, 1994, by the United Nations to prosecute those behind the genocide.

• More than 90 people were indicted and, after lengthy trials, dozens of senior officials in the former Rwandan regime were convicted of genocide, all of them Hutus. Rwanda also set up community courts to prosecute thousands of low level suspects.

Sources: Outreach Programme on the Rwanda Genocide and the United Nations/United Nations International Residual Mechanism for Criminal Tribunals/National Commission for the Fight against Genocide