Inferno spawns poison cloud

Claims by environmentalists that a deadly gas widely used during the First World War was released in a huge chemical plant explosion were denied last night by the plant's owners.

Albright & Wilson insisted that a cloud released over Avonmouth and Gloucester contained no phosgene. Greenpeace had claimed that the gas had been mixed with two other chemicals during the inferno.

Both Severn estuary crossings and the M49, M48 and parts of the M4 were closed yesterday as chemical fallout drifted north east from Avonmouth. Tens of thousands of householders were warned to stay indoors. Avon fire brigade later said the gas would cause only minor irritation.

The alert began at 10.30am with a large explosion at the plant. Five workers and six firefighters were taken to hospital with minor injuries. About 100 firefighters took two hours to bring the blaze under control.