The Brussels suburb of Saint-Gilles was closed off last night (local time) after two explosions were heard.
The explosions appeared to have been caused by a number of cars that were ablaze in a residential area.
There are no official reports yet of what caused the fire or whether it is part of a terrorist attack.
The city is still on edge following the terrorist bombings in March that claimed the lives of 32 people.
Pictures of the chaos have emerged on social media.