Brussels holds vigil at city square

"Brussels I love you" says the message written in chalk on a historic city square, a place for raucous celebration that has become a scene of grief after Belgium's worst terror attack.

Wrapped in the national flag and carrying candles and flowers, Belgians flocked in their hundreds to the Place de la Bourse in the ancient heart of the city to grieve for the dead.

People display a solidarity banner in Brussels following bomb attacks in the city on Tuesday, March 22, 2016. Banner reads "I am Brussels" in French and in Flemish languages. Reuters/Charles Platiau

The European Union's symbolic heart was left reeling Tuesday after some 35 people were killed in bombings at Zaventem Airport and on a metro train.

A lone musician played a cello as a mourner waved a banner reading "United against hate" and another message scrawled on the ground said: "Christians + Muslims + Jews = humanity".

"It's important to get together after moments like these," Leila Devin, 22, told AFP. "It shows we're united against terror."

People light candles and offer flowers at a makeshift memorial in front of the stock exchange at Place de la Bourse (Beursplein) in Brussels on Tuesday, March 22, 2016, in tribute to the victims of the Brussels blasts. The triple bomb attacks in the Belgian capital killed about 35 people and left more than 200 people wounded. The Islamic State group has claimed responsibilty for the attacks. Aurore Belot/Belga/AFP

Belgian Prime Minister Charles Michel joined the mourners after dark fell and European Commission president Jean-Claude Juncker also paid homage to the dead.

"Tonight I am Belgian," he said, full of emotion.

Landmarks around the world, from  New York's One World Trade Center to the Eiffel Tower in Paris were lit up in the black, yellow and red of Beligum's national flag in solidarity.

Near the Place de La Bourse square, the usually bustling pedestrian streets of the city center were nearly empty, with many shops closed.

A stone's throw away, there were no visitors by the iconic Manneken Pis statue of a young boy urinating, usually surrounded by a crowd of tourists waiting in line to snap a picture.

"It's sad, it's unfortunate, it's shocking," said Sofiane, an Algerian student, who had come to pay her respects.

- 'We're not scared' -All day, the sound of police and ambulance sirens echoed through the streets, with roads cut off by heavily armed soldiers and police officers.

As night fell some signs of normalcy returned, with trains running from the main station and some roads opening up.

But on the square, where the country traditionally celebrates the victories of its "Red Devils" footballers, the crowd continued to swell.

Like Belgium's football team, the attacks have sparked a rare moment of unity in a country that is normally deeply divided between its French and Flemish-speaking communities.

"My mother and I came to show we're proud of being Belgian and that we're not scared. Because this morning I was terrified," said Analphia Desmet, a 22-year-old communications student.

As more and more flowers were placed on the square, the crowd joined together to sing John Lennon's "Imagine".

Mourners waved banners saying "Brussels is beautiful" and "Je Suis Bruxelles" (I am Brussels) -- a reference to the slogan that became rallying cry after the attacks on Paris's Charlie Hebdo magazine in January 2015.

"We're here to say we're not scared, there's a dozen of them, but we are thousands," said Belgian student Juliette. —Agence France-Presse