"A nightmare," says Guillaume remembering how it felt to learn about the attacks on Paris the night before. "Except that when you woke up this morning, you realize it was done," he adds.

"Here to support our people even if we are living in London," says Amandine.

Many of the French gathered in Trafalgar Square remember the attacks on Charlie Hebdo last January. Whether they were in Paris in Place de la Nation, or here in Trafalgar Square, the feeling remains the same, no lessons have been learned and it should not have happened a second time.

"It's only been ten months since the attacks on Charlie Hebdo," says Pierre-Olivier, who arrived in London less than a week ago. "And we still haven't learned any lesson", he says.

But all of them agree, they are "not afraid" and will continue to show their support to Paris. "We are not afraid of terrorism," says Marie defiantly.

The vigil in Trafalgar Square took place 24 hours after the attacks on Paris. President Hollande has declared a state of emergency across France, and has deployed 1,500 troops after a near-simultaneous series of explosions and shootings brought Paris to a standstill overnight. Currently, the death toll stands at 127 and around 200 other people were wounded, officials said.