A New Zealander studying in Nice heard screaming and saw people running after an attack in the French city.
Jarryd Walker is an Auckland medical student and is training at a hospital in Nice.
He told RNZ he had been with a friend watching the fireworks, and as they were walking away they heard people screaming and everyone started running.
Mr Walker said he then heard sirens and saw police cars, ambulances and fire engines driving past.
He is back at home and said he and his flatmates were keeping the lights out because of rumours of a gunman in the city.
The Ministry of Foreign Affairs says the embassy in Paris is liaising with the local authorities to see whether any New Zealanders have been harmed in the incident.
It has 882 New Zealanders registered as being in France.
Key tweets condolences
Prime Minister John Key, who is in Paris after attending Bastille Day events and having talks with Mr Hollande, has tweeted his condolences.
Mr Key said "Our thoughts are with the victims of the tragic events in Nice, their families and the people of France".
Our thoughts are with the victims of the tragic events in Nice, their families, and the people of France.— John Key (@johnkeypm) July 14, 2016