Three men wielding wooden sticks carried out a dawn robbery at the Banbury Road Tesco Express in Stratford this morning.
The men, who were all wearing balaclavas, entered the premises at around 7.15am demanding money and cigarettes before fleeing the scene.
The offenders are also beleived to have a stolen a Vauxhall Aguila in the incident.
Police cars remain at the front of the store and the area has been cordoned off with police tape.
An ambulance and paramedic officer were sent to the scene to assess a number of patients, but no injuries were reported.
Detective Sergeant Sutherland Lane said: “Three males with their faces covered entered the store and threatened the people inside. They took cash and cigarettes and left in a black Vauxhall Agila (partial registration NU59) belonging to one of the victims.”
The males are all described as being less than six foot tall and were all wearing dark clothing.
Detective Sergeant Lane added: “Fortunately nobody was injured but this was clearly a distressing incident for the victims.”
Police are appealing for witnesses to the incident and anyone with information should call 101 quoting crime reference number 36 of 12 February.
The store is expected to be closed most of the day.