Nice terror attack: France declares three-day national mourning

France has declared a three-day national mourning from Saturday onwards in the aftermath of the Nice terror attack that killed around 84 people, including foreigners.

The attack occurred when a large truck ploughed into a crowd celebrating Bastille Day in the southern French city of Nice.

Condemning the attack, French President Francois Hollande has said the attack was "undeniably" of a "terrorist nature" and announced the extension of the state of emergency by another three months, reports the Guardian.

"The attack was 'undeniably' of a 'terrorist nature'. The state of emergency that was implemented in the awake of the November terror attacks in Paris and was supposed to end on July 26 will be extended by another three months," said President Hollande.

The driver of the truck was shot dead by police.

Authorities said the man had been firing on the crowd and police as he drove, and that the truck was loaded with weapons and grenades.

Investigations are underway.

Meanwhile, leaders from around the world showed solidarity with France and condemned the attack.