France, April 7 -- Rwanda is commemorating the 1994 genocide, in which 800,000 people, most of them from the Tutsi ethnic group, were massacred by Hutu militias. But this year the event is marked by tensions over Rwanda's alleged support of the M23 rebel group in neighbouring Democratic Republic of Congo.

Every year, Rwanda marks Kwibuka - "Remembrance" in Kinyarwanda - a sombre 100-day commemoration of the genocide which began on 7 April 1994.

President Paul Kagame is expected to pay his respects at theKigali Genocide Memorial, the site where more than 250,000 victims are believed to be buried. He will deliver a speech and light the flame of remembrance, with foreign dignitaries in attendance.

This year's anniversary comes as Rwanda f...