PARIS (Reuters) - France on Wednesday sentenced two former Rwandan mayors to life in prison for genocide and crimes against humanity committed in the African country in 1994.

Tito Barahira, 65, and Octavien Ngenzi, 58, were tried over attacks against ethnic Tutsis in the town of Kabarondo, where they both have been mayor. They denied any wrongdoing.

Ethnic Hutu extremists killed more than 800,000 Tutsis and politically moderate Hutus in a three-month rampage in 1994 while the world largely stood by.

A number of Rwandan genocide-related crimes have been tried in recent years in Rwanda and other countries. This was the second such trial in France, which can rule on such cases since parliament adopted a law that gives it universal jurisdiction over cases of crimes against humanity.

Rights groups welcomed the decision but called for faster trials in other, ongoing investigations. "We need to speed things up, it's high time, it's been 22 years," said Dafroza Gauthier from CPCR, a rights groups of Rwanda victims. "We need procedures to accelerate while there are still witnesses."

Philippe Meilhac, a lawyer for Barahira, said the accused were likely to appeal the decision.

France was an ally of the Rwandan government that ruled before the genocide.

(Reporting by Chine Labbe; Writing by Ingrid Melander; Editing by Larry King)