The man, identified as naturalised Frenchman Khamzat Azimov, carried out the attack Saturday night in a lively area of theatres and restaurants near the city's historic opera house.

Patients were temporarily moved during the bomb squad's investigation, before the hospital reopened in the early evening.

The only surviving suspect in last November's attacks on Paris is set to face an anti-terrorism judge for interrogation, after refusing past questioning in frustration at 24-hour video surveillance of his prison cell.