'People were running from death' in Nice

Sydneysider Marcus Freeman had grabbed an ice cream after watching the Bastille Day fireworks in the French city of Nice with his wife when he heard the sound.

Moments later, he was running for his life.

"The gunfire sounded very close," he told AAP.

"The crowds were hysterical.

"People were running from death."

Mr Freeman said he and wife Sally-Anne were just 15 metres from their Nice hotel when they heard the gunshots.

They ran into their hotel, taking 10 people with them.

Mr Freeman initially wrote on Facebook how he hoped and prayed it was just a panic and no one was hurt.

He soon realised that wasn't the case.

"I cannot believe this."

At least 77 people are dead and many others injured including an Australian woman after a truck containing guns and grenades ploughed into crowds along the French resort city's Promenade des Anglais.

Mr Freeman said he and his wife were in lockdown and safe in their hotel.

The couple were spending the last week of their trip to France in the south.

They now plan to pick up their daughter from Paris and head back to Australia on Sunday.