Brussels attacks: Thousands gather to create improvised memorial with chalk messages of solidarity and defiance

Brussels' Place de la Bourse became an improvised memorial of flags, tea lights, balloons and flowers

Thousands of people gathered outside the stock exchange in Brussels to draw messages in chalk of solidarity and defiance after Tuesday's deadly bomb attacks.

Brussels' Place de la Bourse became an improvised memorial of flags, tea lights, balloons and flowers.

It has become a giant message board for those wanting to express their respect for the victims, with slogans such as "spread love", "Live and Let Live", and "we are one".

People write hundreds of messages on the asphalt at Place de la Bourse in the center of Brussels to mourn for the victims of todays attack, Tuesday, March 22, 2016 (AP)

People gather to leave tributes at the Place de la Bourse following today's attacks on March 22, 2016 in Brussels, Belgium (Getty)

A woman writes a message on the ground as people leave tributes at the Place de la Bourse following today's attacks on March 22, 2016 in Brussels, Belgium (Getty)

A person writes a message as people leave tributes at the Place de la Bourse following today's attacks on March 22, 2016 in Brussels, Belgium (Getty)

Across Europe, monuments have been illuminated with the colours of the Belgian flag in a show of solidarity.

The Eiffel Tower in Paris, Berlin's Brandenburg Gate and the Trevi Fountain in Rome were lit up in the black, yellow and red of the Belgian flag.

The Belgian flag was also raised to half mast over Downing Street.

Images of Tintin, the character created by Belgian cartoonist Herge, have also been shared widely on social media. The term #JeSuisBruxelles trended on Twitter for much of the day.

Additional reporting by agencies