CAIRO (Reuters) - Supporters of Islamic State celebrated on social media an attack in France by a truck that ran into crowds watching a fireworks display on the Bastille Day national holiday, killing at least 73 people and injuring 100.

“The number of those killed had reached 62 french crusaders and sinful infidels in Nice, France.. God is great, God is great,” read one tweet.

The driver drove at high speed for over 100 meters (yards) along the famed Promenade des Anglais seafront in the French Riviera city of Nice before hitting the mass of spectators. The driver was shot dead, sub-prefect Sebastien Humbert told France Infos radio.

Humbert described it as a clear criminal attack. The driver was not yet identified. Residents of the Mediterranean city, which is close to the Italian border, were advised to stay indoors. There was no sign of any other attack.

Almost exactly eight months ago Islamic State militants killed 130 people in Paris. On Sunday, France had breathed a sigh of relief as the month-long Euro 2016 soccer tournament ended without a feared attack.