A HUGE plume of smoke following an explosion dominates the south Essex skyline this evening.

The smoke can be seen from many miles away.

Many residents in the east of county, including Southend and Benfleet report having heard a 'window-rattling' explosion.

An Essex Fire and Rescue Service statement says: "We're currently at the scene of large industrial unit fire in Southend Road between East Hanningfield and Rettendon.

"If you live or are travelling nearby, please keep your windows and doors closed.

"Please avoid the area if you can."

At 6.30pm, the fire service said 100 firefighters from stations across the county were tackling the flames.

People living near the fire - which happened close to the village of Rettendon, south of Chelmsford - were urged to keep their windows closed as smoke spread.

It was not clear whether there had been casualties, but in an update that night, Dave Bond of Essex County Fire and Rescue Service said: "While on the scene, fertiliser inside one of the units exploded and residents across the county have reported hearing and feeling it.

"This is why we declared a major incident, and I want to reassure our residents that there is no wider risk to the public at this time."

He said "everybody at the scene is safe" but that residents have been evacuated.

Update 10:45pm

Around 50 firefighters remain on scene working alongside specialist officers and advisors to put the remains of the fire out in sections.

Area Manager Dave Bond said: "We expect to be here throughout the night and into tomorrow. There will still be visible smoke from the site overnight, but the current wind direction is in our favour, and is drifting up away from homes. If in doubt, and you can smell it, keep your doors and windows closed as a precaution.

"There will be a thorough investigation carried out to find the cause of the fire."

A number of buildings and vehicles on farmland were gutted by the fire, which kept burning into Saturday.