The killings last Friday in the Echirolles suburb of Grenoble sparked outrage in France and prompted President Francois Hollande to travel to the southeastern city late Monday to visit the families of the dead young men.
Hollande was accosted as he visited the poor suburb by a local resident who lambasted security forces for failing to stop the violence she said was plaguing the area.
Interior Ministrer Manuel Valls also travelled to the city and on Tuesday denounced what he called a "massacre" and vowed that the killers would be tracked down.
Kevin Noubissi and Sofiane Tadburt, both aged 21, were beaten and stabbed to death by a gang of about a dozen people in a park.
The gang was reportedly seeking vengeance after a minor incident outside a high school involving Noubissi's younger brother.
Locals were planning a commemorative march in the suburb later Monday to honour the two men, who were said by friends and families to be model students.
Most of those arrested Tuesday in Grenoble were aged between 18 and 21, police said.