(VOVworld) - France observed the first of three national days of mourning on Saturday after at least 84 people were killed in the city of Nice when an attacker drove a truck into a large crowd celebrating national day.

Investigators work at the scene near the lorry that ran into a crowd in the southern city of Nice (Photo: Reuters)

Flags were at half-mast and moments of silence held nationwide. Many tourist attractions were closed while security was enhanced in crowded areas. Along the coastal avenue Promenade des Anglais in Nice, people laid flowers, toys, photos and lit candles to commemorate and pray for the victims.