Moroccan-born Leila Slimani won France's top literary prize, the Goncourt, on Thursday with a novel that "scares the wits out of parents".

"Chanson douce" (roughly translated as "Sweet Song"), is based on the real-life story of a Dominican nanny shortly to stand trial for murdering two children she was looking after in New York in 2012.

The separate Renaudot prize, often seen as something of a consolation prize, went to "Babylone" by Yasmina Reza, best known for her hit play "Art".