Photo: Jean Jullien (@jean_jullien) via Instagram

Monuments and landmarks around the world were illuminated in red, white, and blue—the Tricolore—this weekend, in solidarity with Paris after the city was targeted in an unprecedented attack that claimed at least 129 innocent lives and left 352 injured.

In the wake of the tragic events, French President Francois Hollande declared three days of national mourning. Under the order of the ministry of culture and the prime minister, all museums and cultural institutions in Ille-de-France remained closed over the weekend. The doors of the Grand Palais, where the photography art fair Paris Photo was due to run until Sunday, remained shut.

Photo: Le Petit Prince Officiel via Facebook

“We were expecting another 20,000 people in those two days, and I cannot take the risk,” Jean-Daniel Compain, senior vice president of Reed Exhibitions, which operates the fair, told the Los Angeles Times.

“Considering the human factor, it is very important. This is not just about business […] As all the French people and all the world, we are extremely shocked and sad. What else can I say? It’s a real nightmare.”

Joann Sfar (@joannsfar) via Instagram

He added that many fair visitors attended gallery openings and parties in the Marais district, which borders on the 11th arrondissement where the attacks took place. Several were left stranded until the early hours. “People were standing in galleries until three or four or five in the morning because they couldn’t leave,” Compain said. “They told everybody to stay inside. It was total confusion.”

Photo: Jaume Capdevilla (@globalcartoons) via Twitter

Soon after the events unfolded, artists and cartoonists around the world grabbed their pencils and brushes to create tributes to the victims of the attacks. An illustration by Charlie Hebdo cartoonist Joann Sfar, calling for the hashtag #ParisIsAboutLife, was shared widely, while Jean Jullien’s Peace for Paris composition quickly went viral online.

In response to the massacre during a concert by the American rock band Eagles of Death Metal at the Bataclan theater, musicians around the world canceled gigs to pay tribute to the victims of the attack.

Andre Saraiva (@baronandre) via Instagram

According to the BBC, U2 called off a scheduled performance in the French capital choosing instead to pay their respects by laying flowers near the Bataclan.

The Foo Fighters, who were scheduled to perform in Paris on Monday, canceled the remainder of their European tour, while Motorhead, scheduled to perform on Sunday, postponed their Paris concert to January.

The hashtag #MonPlusBeauSouvenirDuBataclan (my most beautiful memory of the Bataclan) was created on social media to reclaim the venue’s name, and quickly became the top trending hashtag in France.

Photo: Osama Hajjaj (@osamacartoons) via Twitter

Meanwhile, Madonna abruptly halted her show in Stockholm on Saturday to perform a tearful rendition of the French chanson La vie en rose.

At New York Metropolitan Opera, star tenor Placido Domingo led the orchestra’s stirring delivery of the French national anthem before opening their performance of Puccini’s Tosca on Saturday.

Carlos Latuff (@latuffcartoons) via Twitter

Many cultural institutions including the Louvre and the Musee d’Orsay, which were closed on Saturday as security was tightened, reopened to the public Monday.