At least six people were killed and many others injured after a fire ripped through a high-rise apartment building in the Belgian city of Antwerp on Wednesday, authorities said.

Police said the blaze was triggered by a technical malfunction on the ground floor of the 10-storey residential building in the Linkeroever district. The building contains about 80 apartments and houses more than 200 residents.

The fire spread rapidly, sending thick smoke into the air, with the upper floors appearing to suffer the heaviest damage. Emergency crews evacuated the building, while residents in the surrounding area were advised to keep their windows and doors closed and switch off ventilation systems because of the smoke.

Those forced to leave the building were taken to a temporary shelter.

Firefighters battled the blaze under difficult conditions due to its intensity, with multiple firefighting, police and emergency medical teams deployed to the scene. A specialized drone unit also assisted the operation.

A medical emergency plan was activated to ensure nearby hospitals could cope with the large number of casualties.

Television footage showed one resident leaning over a balcony amid dense smoke in an apparent attempt to breathe before moving to a nearby window.

By early afternoon, the fire had largely been brought under control, although emergency personnel remained at the scene.

Belgian Prime Minister Bart De Wever expressed sympathy for the victims and displaced residents, while thanking firefighters and other emergency responders for their efforts to rescue those affected and contain the blaze.

Authorities have launched an investigation into the incident.

Linkeroever, located on the western bank of the Scheldt River opposite central Antwerp, is a densely populated residential district known for its high-rise apartment buildings and large public park.