A cigarette end started the fire which caused the evacuation of hundreds of shoppers and staff in Oxford city centre, an investigation has concluded.

The fire started in Eyesite optician on Saturday, June 29, but quickly spread through part of a three-storey block of shops in St Ebbe's Street.

The cigarette was discarded in a small metal bin used as an ashtray by smokers on a first floor flat roof area, to the rear of the building.

But it was not put out properly, and cigarette packets, butts and other rubbish smouldered over three to four hours before the fire spread.

Station Officer Steve Harrison, who investigated the fire, said: "It was an accidental fire. It's just one of those things, unfortunately."