A fire service investigation has revealed the cause of a blaze that led to a building being evacuated.

Herts Fire and Rescue Service were called to Robert Court, off Tolpits Lane, at around 3.45pm on Monday (July 24) before a road closure was put in place and the building was evacuated.

It has since been revealed that the fire, which did not result in any injuries, was started accidentally by a “carelessly discarded” cigarette.

The blaze had started in a bin shed attached to the building and, according to eyewitnesses, it went up "very quickly" before being extinguished by 4.30pm.

Firefighters remained on scene until 5.50pm to damp down the area.

During the emergency, Robert Court residents gathered outside Viking Fish & Chips and Kebabs, opposite the block, with some apparently thinking the building itself may have caught light.

Watford Observer:

People were seen in robes or without shoes and some bought fish and chips while waiting for emergency services, the takeaway's staff said.

Others reportedly ran to move cars away from the shed, which is next to the car park.

A pharmacist at the nearby Greenfield Pharmacy said: "A customer came to us and said 'there's a fire outside!'."

He then saw the smoke and huddled people outside.

Watford Observer:

"I went out to see if I could help, because I’m the pharmacist, but it seemed like everyone was ok," he added.

Labour county councillor Nigel Bell said: “As the local county councillor I am relieved that there were no injuries and would like to praise the local fire and rescue team for their professional work as ever and also praise the care shown by local residents in trying to help as best they can.”

Smoke rising from the shed could be seen from far away in videos shared by locals, and images from the scene showed the shed well alight.

Herts Police were called at 3.50pm and attended the scene to put the “full road closure” in place and evacuate residents from their homes “as a precaution”.