An Australian couple who witnessed the horrifying Nice attack have described how they told their children the sound of gunshots was just fireworks.

Melbourne parents Danae and Sasha Goldsmith, who work in the wine industry, were in the southern French city with their two daughters when the terror attack occurred on 14 July.

The family had just finished watching the Bastille Day fireworks from the balcony of their Airbnb apartment when the carnage unfolded.

For current updates on the Nice attack, see this post.

“The fireworks were going on and they were all lovely … there were thousands of people on the streets,” Ms Goldsmith told The Age.

“We weren’t going to go down into the crowds because my little girls being too little.”

When the celebratory fireworks finished about 11pm, the family went inside to pack for their next flight.

"[T]hen it went a bit quiet, a bit eerie. I just noticed 'what? why has all the music stopped?'," Ms Goldsmith told The Age.

"And then a truck was coming down the promenade and I thought 'that's weird, there's no cars allowed because of the celebrations'.

"Then I realised what the truck was doing."

Let's pray for Nice. Post continues after video...

Ms Goldsmith described the terrifying moment the 25-tonne lorry accelerated through the crowd of thousands, deliberately running down dozens of revellers.

"Everyone was scrambling, like little ants running away from something," she told The Age.

"I saw the people get mowed down, and the truck stopped just outside our apartment."

As gunshots continued to sound outside -- presumably the shoot-out between the attacker and policeman that ended with the terrorist's death -- the family sat with heads bowed.

Ms Goldsmith ultimately told her daughters, aged five and seven, that the loud sounds had been a fireworks incident.

She put them to bed, not wanting to expose them to the bloodshed unfolding immediately outside their apartment block.

Earlier, Ms Goldsmith described to Nine Network's Today Show how the children were completely oblivious to the attack.

"We got them (the children) down and... told them it was fireworks,"Mrs Goldsmith told the Nine Network's Today Show. "We said sometimes people put fireworks up in the crowd."

Ms Goldsmith also live-blogged the chilling incident on Facebook.

"Terrorists outside our balcony...gunshots, people killed... barrackaded in apartment, truck is outside," she wrote.

She continued: "Can't get out apartment...got to get the girls away...just need to keep girls ok."

The family eventually safely made it out of France and to the UK.

Ms Goldsmith this morning wrote online that social media had proven useful during the ordeal.

"Never used social media so much and never hope to again," she wrote. "To be able to get information from the outside world when we were locked up inside feeling very alone was incredible."

She ended with a poignant message to all readers, reminding them to take a moment to appreciate their loved ones.

"Hug all those you love and even those who don't love you, and wish them safety and health always."

For current updates on the Nice attack, see this post.

Concerned about friends or family? Call DFAT: 1300 555 135 or +61 2 6261 3305 (if outside Australia)

(Feature photo: Facebook)