The father and three roommates of the attacker were detained and being questioned in the capital, Tunis, Interior Ministry spokesman Mohamed Ali Aroui told The Associated Press. The attacker has been identified as Seifeddine Rezgui, a 24-year-old graduate of Tunisia's Kairouan University where he had been living with the other students.
"We are sure that others helped, but did not participate," Aroui said. "They participated indirectly."