The Westgate Shopping Centre was evacuated this afternoon after a “joke shop firework” was let off.

The children’s toy was set off in clothes retailer Primark and led to the entire centre being evacuated at about 3.50pm for approximately 40 minutes.

Westgate general manager Brendan Hattam said: “We had to evacuate as a precaution because we had a little bit of smoke in the Primary unit which was caused by a joke shop fire work - the kind of thing you would buy in a joke shop.

“It was not a big thing but it was just enough smoke for us to be suspicious enough to evacuate as a precaution.”

He added: “We have been speaking to the fire service and police and we are reviewing CCTV. It looks like a prank.”

He said any prosecution would be done after discussions with Primark and Thames Valley Police, which said was investigating the incident.