Four masked robbers completed two armed robberies before burning out their getaway car in Cleckheaton last Thursday evening.
Four suspects armed with weapons forced their way into a petrol station on Leeds Road, Dewsbury, at around 9.45pm and threatened staff before stealing cash.
They left the scene in a green Ford Focus and no one was injured in the incident.
Just 15 minutes later, Police were then called to the Londis convenience store on Westgate in Cleckheaton.
Police say CCTV footage shows three males with their faces covered getting out of a green Ford Focus entering the shop then threatening a member of staff.
The shop worker was hit in the head with what is believed to be a hammer and the suspects made off with cash from the till.
The victim was taken to hospital with non-serious injuries and was released a few hours later.
Sources close to the victim said that both he and his partner are extremely shaken up by the incident.
The getaway vehicle was torched and recovered from the Greenway, just off Mount Street, a short time later.
Police are appealing for anyone who saw a green Ford Focus 52 plate driving in the area at the time or anyone acting suspiciously to call Kirklees CID on 101, quoting crime reference numbers 13180470720 or 13180470770.
Information can also be given anonymously to the independent Crimestoppers charity on 0800 555 111.