Nineteen people were treated in hospital after a cash-box security device was accidentally activated inside a supermarket yesterday.
Warwickshire Police said the casualties suffered temporary breathing difficulties and eye irritation after the device spewed out a cloud of purple dye inside an office at the Morrisons store in Alcester Road, Stratford upon Avon.
Emergency services were alerted shortly after 11.30am and the supermarket was evacuated. A police spokesman said: "It's believed that a security device on a cash-box accidentally activated, causing a cloud of purple dye to be discharged into the accounts department office, where staff were working.
"It is unclear why the security device activated but police are not investigating any crime or treating the incident as suspicious."
Nineteen people - thought to be staff members - suffered temporary breathing difficulties and eye irritation and were taken by ambulance for precautionary treatment at hospitals in Warwick and Redditch.