According to the prosecution, the victim was killed by blows received in the head during a clash between rival gangs from Coignières and the neighboring town of Maurepas.

The blows could have been struck with a hammer, according to a police source.

The victim is from the Friches district in Maurepas, a town of about 17,000 inhabitants. A second youngster, also from Maurepas, was slightly injured.

The victim died shortly after paramedics arrived, despite their attempts to resuscitate him.

The two cities, with a rather quiet reputation despite some sensitive neighborhoods, are located on the edge of the forest, about fifteen kilometers from Versailles.

Nothing raised fears of a particular excess of violence on Saturday evening.

“It’s been a year since it was calm between these two neighborhoods,” said a source familiar with the matter.

The brawl broke out around midnight, between two members of two rival gangs, outside, after an evening of MMA fights organized in a gymnasium in Coignières.

“It was a family event, with many children. The father of the victim was also present at the evening”, underlines the source close to the file.

No suspects had been arrested Sunday morning.

According to the first elements of the investigation, witnesses had locked the alleged perpetrator in the gymnasium, but he managed to escape through a window.

The investigation, opened for intentional homicide, was entrusted to the judicial police of Versailles.