Hollande has said that one of the victims, three women with links to the outlawed Kurdistan Workers Party (PKK), was known to him.

The execution-style killings in central Paris on Thursday have overshadowed a new initiative by Erdogan's government to launch a peace process to end the PKK's 28-year-old insurgency against Turkey.

"France needs to shed light on this incident," Erdogan said in a speech to a businessmen's group on Saturday.

"The French president needs to explain to the public in Turkey and the world why he met with members of a terrorist organisation."

His comments were broadcast live by CNN Turk television.