PARIS, May 31 (Reuters) - French security forces arrested earlier this month in Saint-Etienne an 18-year old Chechen suspected of planning an attack at the city's soccer stadium during this summer's Olympic Games, Interior Minister Gerald Darmanin said.

Less than two months before the Olympic Games, France is on its highest state of security alert.

"The first elements show he was actively planning an attack against the Geoffroy Guichard stadium (Saint-Etienne) during the soccer matches that will take place there during the Olympic Games" Darmanin said in a statement.

The suspect was "inspired by the Islamist" ideology, he said.

"He wanted to attack spectators, but also security forces and die as a martyr," Darmanin added.

This is the first foiling of an attack planned in connection with this Summer Olympics, the statement said.