A shopper filmed the aftermath of a robbery at an Oxfordshire jewellers where a "have a go hero" detained one of the suspects.

Police said a gang, armed with a hammer, had stolen high value watches from a shop in Banbury's High Street.

A passer-by intervened and was helped by other members of the public to pin down suspects until police arrived.

Witnesses of the robbery, at 10:40 BST, should contact Thames Valley Police.