23/03/2016 10:05 AM AEDT

Bells And Singers Fill Brussels With The Sound Of John Lennon's Imagine

"Hope must survive."

Carl Court/Getty Images
A young girl lights a candle for the attack victims at the Place de la Bourse in Brussels. Some began to sing John Lennon's Imagine, while across the city, a historic library pealed bells in a gesture of solidarity and hope.

After a day of bloodshed in Brussels, crowds gathered in a central square to leave flowers, messages and candles for over 30 dead in attacks claimed by the Islamic State militant group.

Some of them held hands. Others wept. Then, some people began to sing. 

Videos posted on social media showed a circle of people arm-in-arm quietly singing John Lennon's "Imagine" at the Place de la Bourse, a popular meeting place right in the center of the city, on Tuesday evening.

By the end of the day the square had become a makeshift memorial to the victims and a love letter to Brussels, the ground covered in chalk messages of hope, anger and unity, and strewn with candles and flowers.

Belgian Prime Minister Charles Michel visited the square late Tuesday to light a candle for the dead.

#bourse #prayforbrussels #imagine #brusselsattack #stillpissing #💪

A video posted by Jérémy Calloud de Faudeur (@jebcalloud) on

Across the city, the same song pealed from a bell tower of the historic library of Brussels' oldest university as night fell.

"Hope must survive," the University of Leuven wrote in a Twitter post about the gesture of solidarity with the grieving city.

Photo gallery Explosions In Brussels See Gallery