PARIS: French President Francois Hollande said Friday (Jul 15) that an attack which saw a truck plough into a crowd in Nice, killing 80 people, was clearly a "terrorist" act.

Hollande said several children were among the dead and 20 victims were in a critical state after the attack, which he said was of an "undeniable terrorist nature".

The President also vowed to strengthen his country's role in the fight against the Islamic State (IS) group in Iraq and Syria after a deadly attack on Nice, which has not been claimed by any group.

"Nothing will make us yield in our will to fight terrorism. We will further strengthen our actions in Iraq and in Syria. We will continue striking those who attack us on our own soil," he said, in reference to IS.

Hollande also added that he had called on reservists to boost the ranks of police and gendarmes. France's "operational reservists" include French citizens with or without military experience as well as former soldiers. Hollande said they would in particular be used to boost "border controls".

The state of emergency, which has been in place since November's attacks in Paris, and was due to be lifted on Jul 26 would now been extended for another three months, the President said in his televised address to the nation.