Details of the two suspects were relayed to police stations across the country amid fears they could try and flee overseas, sources close to the probe said.
One of them, named as Ilyas T., turned himself in at police headquarters in the southeastern city of Grenoble, where Kevin Noubissi, and Sofiane Tadburt died last Friday after being stabbed and beaten.
Ilyas T., 18, and the second suspect Ibrahim C., 20, were "known for their extreme violence", said prosecutor Jean-Yves Coquillat.
Eight people have so far been charged with murder as a result of the attack which prosecutors believe involved between 10 and 15 people.
Ilyas T. had just been released from prison last week after serving a sentence for stabbing a supermarket security guard while Ibrahim C. is the subject of an ongoing legal case over an alleged knife attack at a cashpoint.
Noubissi, a student, was stabbed seven to eight times, and Tadburt, a tutor, 30 times in an attack that has been greeted with shock throughout France and intensified concern over juvenile delinquency in peripheral urban areas.
The gang was reportedly seeking vengeance after an incident outside a high school involving Noubissi's younger brother "looking the wrong way" at another teenager.
Funerals for the two friends took place Wednesday at the local mosque in Grenoble with hundreds of mourners attending.