Paris: A man was detained on suspicion of planning an attack on the Olympic torch relay in Bordeaux on Thursday, French Interior Minister Gérald Darmanin has said.
The suspect had sent a threat letter, wherein he referred to a previous mass killing in the US, the investigating agencies said.
The prosecutor said the suspect - named as Alex G - had no criminal record but during a search of his home a rubber pellet revolver was seized along with several mobile phones and a computer.
According to the court in Bordeaux, the suspect had admitted to "having considered an act with no specific location" in mind, and had not directly spoken about the Olympic flame relay.
The Olympic flame arrived in Marseille earlier May, ahead of the Paris Games that start on July 26. Unprecedented security operation is afoot for an opening ceremony involving over 10,000 athletes being ferried along the River Seine, the BBC report said.
The Olympic flame was due to arrive in Bordeaux late on Thursday afternoon, after a day of events marking its passage through the surrounding area.
The Flame is at the start of a 12,000km "odyssey around mainland France and its overseas territories", the report said. Anti-drone experts have joined police in keeping a close eye on its journey.
The flame was due to travel as far as the Pacific territory of New Caledonia, but rioting over the past 10 days has prompted organisers to cancel that leg, the BBC said.