Footage has emerged of raging car fires and explosions in Brussels as firefighters battled to control the blaze that eventually spread to nine vehicles.

The Belgian daily Dernier Heure reported the huge fire appears to have been the result of an arson attack and, while no suspect has been identified, police are not treating the incident as a terror attack.

The rapidly spreading inferno was started in Adolphe Demeur Avenue in Saint-Gilles, near the European Parliament building and the district of Molenbeek, where the Paris and Brussels Islamic State attacks were spawned.

The Belgian prosecutor's office has confirmed that no individuals were injured in the fires and subsequent explosions. Residents nearby posted on social media that they heard two or three explosions before the flames were brought under control.

The fires were finally put out at 1:30am with emergency services working until 3am to remove the wreckage of burnt-out cars, according to Brussels police.

A spokesman for the fire department in the Belgian capital explained the explosions were not necessarily deliberate and may have been caused by fuel or flammable gasses in the cars.

"A burning car can cause an explosion if the fuel tank is nearly empty or if certain flammable objects, such as sprays, are present," Pierre Meys explained. "This can cause small explosions, but that's pretty minor," he said.

The Brussels public prosecutor ordered a full investigation into the fire, including interviews with witnesses and analysis of CCTV footage.

Convictions under Belgium's criminal code for arson offences range between 10 to 15 years imprisonment.