Paris Attacks
Londoners, Parisiens and British Muslims stand shoulder-to-shoulder in a poignant vigil in Trafalgar Square Twitter

There were emotional scenes in Trafalgar Square this evening, as Londoners stood shoulder-to-shoulder with French citizens and British Muslims, in a powerful display of solidarity in defiance at the attacks that have stricken Paris.

Just 24 hours after eight terrorists, acting on behalf of terror group Islamic State, unleashed a wave of violence across the French capital, hundreds of people gathered in a sombre vigil to honour those who died so tragically and so needlessly.

Paris attacks
British and French people gathered at London's Trafalgar Square in a show of support for Paris and the victims of a wave of terror attacks in the French capital AFP/Getty

United in grief, they raised the French Tricolore high, as they gathered outside the National Portrait Gallery, which was festooned in the red, white and blue of the French flag. People chanted ´solidarité!' as they held home-made banners, declaring their unwavering support for the city of love and light, that today is shrouded in darkness. "Paris Je Taime," "Nous Sommes Paris" they wrote.

Others carried paper hearts, symbolic of the shared sense of loss at the act of barbarism that unfolded on the streets of Paris leaving hundreds dead. A Parisien Muslim woman stood alongside the British citizens. "We have to show those murderers that we are united. We won't let them divide us," she said.

In a poignant moment, the crowd raised their mobile phones in unison, illuminating the scene in a magnificent display of lights for a moment of silence to honour the dead.

A lone violinist then played a stirring piece of music that captured the collective pain in the face of such brutality. "It was moving, beautiful and tragic," one person tweeted while watching the scene.

As the tragedy sinks in, tributes are being paid by people from every walk of life, incensed by the killings.

Singers Madonna, Taylor Swift, Justin Bieber, Katy Perry, French footballer Thierry Henry, actor Hugh Jackman, One Direction stars Harry Styles and Niall Horan and British football icon David Beckham joined the thousands who paid their respects to the victims.

The former England captain shared a photo of the Eiffel Tower today he wrote: "As the sun rises in this beautiful city we remember the people that have died and the families that have lost loved ones... Our thoughts are with you all... PrayForParis."

The sporting world showed its respects, observing a period of silence in Ukraine and Sweden ahead of this evenings play offs. French flags adorned the sidings, bearing the message: "We are with you Paris." While Wembley Stadium was lit up in the colours of the French flag, it was confirmed that a friendly match between France and England will go ahead. In Australia, meanwhile Jets supporters stood in silence at Hunter stadium.

Paris attacks
Jets supporters stand for a minutes silence after the Paris terrorist attacks during the round six A-League match between the Newcastle Jets and the Central Coast Mariners at Hunter Stadium on November 14, 2015 in Newcastle, Australia. AFP/Getty

The music world responded by stopping the music. Irish band U2, who were due to headline the Bercy Arena on Saturday, yesterday announced to fans they would be postponing the concert until 'an appropriate time.'

"We watched in disbelief and shock at the unfolding events in Paris and our hearts go out to all the victims and their families across the city tonight," they said in a statement. "We are devastated at the loss of life at the Eagles of Death Metal concert and our thoughts and prayers are with the band and their fans. And we hope and pray that all of our fans in Paris are safe."

Today, joining a city in mourning, the band members attended a candlelit memorial in the city centre, their heads bowed in respect as they placed flowers at the site of a makeshift memorial.

Paris attacks
Irish band U2 (From L) lead singer Bono, bass player Adam Clayton, drummer Larry Mullen Jr and guitarist The Edge pay homage to attacks' victims near the Bataclan concert hall on November 14, 2015 in Paris, a day after a series of coordinated attacks in and around Paris AFP/Getty

The Foo Fighters too have been forced to cancel the remaining dates of their European tour, following the tragic terror attacks in Paris. Taking to Facebook, the band - fronted by Dave Grohl - said: "It is with profound sadness and heartfelt concern for everyone in Paris that we have been forced to announce the cancellation of the rest of our tour."

Coldplay also cancelled a live-stream show which was due to happen in LA. They said in a statement: "Tonight's live stream for TIDAL & KROQ has been postponed out of respect for the terrible events in Paris. All tickets will be valid for the rescheduled show, with details to follow soon."

Paris attacks
A heart shaped sign with the colors of the French flag is held as people hold a vigil for victims of the Paris terrorist attacks in Trafalgar Square on November 14, 2015 in London AFP/Getty

Hollywood has leant its voice in decrying the attacks. Actress Kate Hudson shared a photo inscribed with the Gandhi quote: "There is no path to peace, peace is the path." It was announced that promotional appearances for Natalie Portman's new film, Jane Got a Gun, were postponed. The actress was scheduled to appear at the film's premiere in Paris on Monday.

Mumbai knows too well the prevailing sense of despair in the aftermath of a terror attack. The November 26-29, 2008 attack, in which ten terrorists killed 164 and wounded more than 300, left the vibrant Indian city paralysed. The Paris attacks are a stark reminder of their personal tragedy and also their resilience, as they rebuilt their city.

Bollywood stars Priyanka Chopra, Shabana Azmi, Javed Akhtar, Shekhar Kapur, Anil Kapoor and Sonakshi Sinha sent prayers and condolences to the victims on Twitter, calling it a day of "sadness".

President Hollande has declared three days of mourning in France, as his citizens attempt to comprehend the tragedy that has befallen them. But as the death toll rises, as the names and faces of those who were killed are daily released, as grieving families begin the agonising task of recovering the bodies of their loved ones, the world mourns, interminably.