GENEVA (Reuters) - Switzerland is sending a Tunisian couple who include the brother of the presumed knife attacker at Marseille train station in France back to their home country for security reasons, Swiss federal police said on Tuesday.

Earlier on Tuesday a source close to the investigation said police detained two Tunisians on Sunday wanted in connection with the attack on Oct. 1 in which the assailant was shot dead by a French soldier after killing two young women.