More than 150 firefighters were Tuesday tackling a huge blaze at a London warehouse thought to contain fireworks, a fire brigade official said.

The fire, which was discovered at around 9:00 am (0900 GMT), ignited at a two-storey building containing a warehouse and retail space, sending up a plume of smoke visible across the west of the British capital.

No injuries were however reported by Tuesday evening.

“As crews carried out firefighting operations, explosions were reported at the scene. These explosions likely involved cylinders and fireworks stored in the affected structure,” said Pat Goulbourne, assistant commissioner of the London Fire Brigade.

Wasim Ismail, who works at a local garage, told AFP he had heard bangs that were “very loud … louder than shotguns going off”.

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He said there had been “if not thousands, at least hundreds of explosions … you could actually see shrapnel being shot across (the site) as they were exploding”.

Neighbouring properties, including three schools, a residential block and an industrial estate were all evacuated.

The roof of the warehouse collapsed, and as night fell about a quarter of the building was still alight, although the “major incident” declared by the fire brigade had been stood down.

Residents at nearby properties were advised to keep their doors and windows closed.