Police are appealing for witnesses after two knifepoint robberies in Avonmouth and Burnham-on-Sea.
In the first incident, at 2115 GMT on Wednesday, at least three men with hats and scarves covering their faces went into a convenience store in Westbury Lane, Avonmouth.
They threatened a member of staff with knives and forced her to hand over cash and cigarettes before getting into a car which was parked nearby with two other people inside.
The gang then sped off in a K-reg Vauxhall Cavalier driving south along the M5 to the motorway service station at Sedgemoor near Burnham where another robbery took place.
Again three men, with their faces covered by scarves, held up staff with knives before taking cash and cigarettes.
The car they used, which had been stolen from the Bristol area earlier in the day, has since been recovered by police.
Police investigating the raids say although nobody was seriously injured members of staff were left very shaken by the incidents.