France has called on young “patriots” to join the reserves following a terror group Islamic State-claimed truck attack in Nice which killed 84 and prompted tough questions over security failures.

Interior Minister Bernard Cazeneuve made the appeal for volunteers to boost the security service as France reels from its third major Islamist attack in the past 18 months.

The call came as the government faces searing criticism over the Thursday attack, in which Tunisian Mohamed Lahouaiej-Bouhlel ploughed a truck into a crowd of people who had been watching Bastille Day fireworks in the French Riviera city.

Some 300 people were injured in the assault and many remain in a critical condition.