In a show of solidarity with Belgium, Paris's iconic landmark, the Eiffel tower was illuminated in red, yellow and black. The announcement was made by mayor of the French capital, Anne Hidalgo via Twitter.

"In solidarity with the people of Brussels, Paris will light up the Eiffel Tower in the colours of the Belgian flag tonight," said Paris Mayor Hidalgo. Hidalgo used the hashtag #NousSommesUnis at the end of her tweet, meaning "We Are United." Following the illumination, Hidalgo tweeted: "Paris and Brussels united. The Eiffel Tower is illuminated in the colours of Belgium."

Belgian flags were also raised alongside French flags at the official residence of French President Francois Hollande. French newspaper, Le Monde, also dedicated their front page to Brussels by depicting a cartoon showing a person draped in the French flag with an arm around another wearing the colours of the Belgian flag. The dates of the Paris and Brussels attacks were inscribed: November 13 and March 22.

Four days after the arrest of Europe's most wanted man, Salah Abdeslam, Brussels was targeted by multiple explosions that claimed at least 31 lives and left over 200 injured. Islamic State (Isis) has claimed responsibility for the attacks on Brussels' airport and a metro station.

The World Trade Center in New York will also display the colours of the Belgian flag, state governor Andrew Cuomo announced via Twitter.

Here's a look at other iconic monuments that have lit up in solidarity with Brussels: