Social media video and pictures show smoke rising from an industrial estate on Orient Close in St Albans, north of London. It was reported by residents an explosion took place earlier in the morning.
Images show Hertfordshire Fire and Rescue are in attendance, supported by Hertfordshire Police.
Simon Tuhill, Assistant Chief Fire Officer for Hertfordshire Fire and Rescue Service, said: “Fire Crews are dealing with a significant fire on London Road in St Albans.
“Please stay clear of the incident and keep your doors and windows closed if you’re in the vicinity.”
Hertfordshire Police said on Twitter at 11.47am: “We are currently assisting the fire service at the scene of a fire in Orient Close, St Albans.
“Closures are in place on surrounding roads and people are asked to please avoid the area.”
Hertfordshire Highways added the A1081 London Road is closed in both directions due to a “building fire”.
They confirmed emergency services are on the scene and urged locals to avoid the area.
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