The mayor of Paris tweeted that the Eiffel Tower will be lit up in black, yellow and red in solidarity with Brussels following a series of deadly attacks Tuesday that left at least 31 dead and dozens injured.

Anne Hidalgo wrote on Twitter, “In solidarity with the people of Brussels, Paris will light up the Eiffel Tower in the colors of the Belgian flag tonight.” She added the hashtag #NousSommesUnis, which means “We Are United.”

The town hall of Brussels lit up with the colors of the French national flag at the Brussels Grand Palace in November following terrorist attacks in Paris.

The town hall of Brussels is illuminated with the colors of the French national flag, at the Brussels Grand Place, on Nov. 14, 2015, a day after deadly attacks in Paris. James Arthur Gekiere—AFP/Getty Images

The Belgian capital has been on high alert since the Paris attacks, when Salah Abdeslam, a suspect, fled to Brussels. He was arrested on Friday.

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