Four armed men rob Asda supermarket in Biggleswade
Four masked men armed with copper pipes designed to look like firearms threatened staff at an Asda store and stole a "substantial amount of cash".
The group arrived at the Church Street, Biggleswade, supermarket at about 22:00 GMT on Saturday, as staff were cashing up the day's takings.
They assaulted a security guard, who suffered minor injuries.
Bedfordshire Police said the men left in a dark blue Audi A4, driven by a fifth offender.
The vehicle, which had false number plates, has since been recovered.
Armed response vehicles were called to the area as soon as the alarm was raised and an extensive search carried out but without success, a spokesman said.
Anyone with information is asked to contact police.