'Not clear' what caused Rackheath explosion
Fire investigators have said they are still not certain what caused an explosion that destroyed a cafe on an industrial estate in Norfolk.
The explosion at Rackheath near Norwich on Wednesday night was heard in villages several miles away.
Norfolk Fire Service said the explosion, which severely damaged several other buildings on the estate, was not being treated as suspicious.
Fire investigator Jonathan Wilby said experts were still examining the site.
He said: "We've done a preliminary investigation and spoken to the owner of the cafe premises to get details.
"But it would be unfair of me to speculate on any cause of the explosion at this stage."
Several other business owners on the estate said they were concerned for the future, saying they had been denied access to their premises until the investigation is concluded.
Others said they had seen their buildings so badly damaged they were unusable and were likely to be out of business until insurance claims were paid.
Jonathan Neville, who runs a printing company on the estate which has started work again, said he was taking extra safety precautions after the explosion.
He said: "We've double-checked machines and systems linked to the fire service.
"We've made sure our fire suppressor safety equipment is up and running. We do these checks anyway but we're making doubly sure now."