Former French president Nicolas Sarkozy broke his silence Thursday over corruption allegations threatening his chances of a political comeback, angrily fighting back against a phone-tap scandal and comparing his country to a dictatorship.

The 59-year-old has found himself at the heart of an increasingly tangled web of scandals, culminating with revelations in the press this month that he allegedly attempted to pervert the course of justice -- information reportedly gleaned from excerpts of tapped phone conversations with his lawyer.

Rwandan doctor Charles Twagira was on Thursday charged in France over the 1994 genocide that claimed some 800,000 lives, a judicial source said.

Twagira was a head of the main hospital in Rwanda's western city of Kibuye at the time of the unrest.

French President Francois Hollande said Europe's leaders would cancel a June summit with Russia and decide fresh sanctions against Russian figures as he arrived Thursday for a European Union summit.

Saying events in Ukraine and Crimea were "unacceptable", the French leader said "sanctions will be decided against a certain number of figures, regarding their personal situation or their financial assets".

French soldiers have killed about 40 Islamist fighters, including some senior commanders, in Mali in recent weeks, Defense Minister Jean-Yves Le Drian said Thursday.

"We have conducted operations over the past weeks," Le Drian said, adding that "about 40" fighters had been killed including "Ould Hamaha, a historic leader of AQIM," or al-Qaida in the Islamic Maghreb.

Nicolas Sarkozy appeared to sink deeper into trouble Wednesday after fresh evidence emerged of an alleged attempt to influence judges involved in one of a string of corruption cases the former French president is embroiled in.

Investigative news website Mediapart published what it said were extracts from tapped phone conversations between Sarkozy and his lawyer, who at one point refers to two top judges as "bastards."

The French commander of a European Union peacekeeping force which had been due to deploy in the Central African Republic this week said Wednesday he did not have enough soldiers.

"The deployment hinges on the creation of a logistical unit of around 100 forces," General Philippe Ponties told French radio RFI, describing the shortage of volunteers as "worrying".

Pascal Simbikangwa, the first Rwandan to be tried in France over his role in the devastating 1994 genocide, has appealed his 25-year prison sentence, his lawyers said on Tuesday.

The 54-year-old former army captain was sentenced on Friday after a landmark six-week trial that was closely watched in France, which was accused of failing to rein in the Rwandan regime at the time of the genocide that left 800,000 dead.

Britain warned Tuesday that the West and Russia faced a changed relationship in the coming years, as London suspended all bilateral military cooperation and halted arms exports to Russia.

Foreign Secretary William Hague said President Vladimir Putin had chosen the "route of isolation" by signing a treaty annexing Crimea just two days after a hastily arranged referendum on the breakaway peninsula.

Dozens of Greenpeace activists sneaked into a nuclear power plant in eastern France at dawn Tuesday in the latest break-in by the environmental group to highlight alleged security weaknesses at atomic facilities.

The activists broke into the Fessenheim plant and hung a banner reading "Stop risking Europe" on the side of one of its reactors "to denounce the risk of French nuclear power for the whole of Europe," the group said in a statement.

French prosecutors on Friday charged two women over the disappearance of a 15-year-old girl who is believed to have traveled to Syria to fight alongside jihadist rebels.

The pair were charged by a Paris court with complicity in criminal association in relation to a terrorist undertaking, a judicial source told AFP.