Officers from North Yorkshire Police are investigating possible links between the two raids, when armed robbers swooped on a jewellery store in the North Yorkshire spa town yesterday morning after a petrol station was targeted the previous evening.
A North Yorkshire Police spokesman confirmed they were liaising with other forces to discover whether the criminals involved in the robberies could be responsible for crimes elsewhere.
He added that while it was too early to say whether the raids were definitely linked, officers would be investigating if the same gang was responsible for both offences.
In the raid on the family-run Bradleys Jewellers in Princes Street, Harrogate, a three-man gang armed with a handgun fled with the largest haul in the company's 37-year history.
Manager John Dykes and his colleague Joyce Smith had attempted to fight off the gang of three men, who had burst into the store at about 9.30am yesterday.
Owner Peter Bradley, who owns five jewellery stores throughout North Yorkshire with his wife, Janet, said: "Both members of staff showed immense bravery and I cannot thank them enough for all that they did to try and stop the robbery.
"They were obviously very shaken afterwards, but thankfully neither of them was seriously injured."
One of the gang was black, and it is thought a fourth man could have been involved.
No shots were fired and a red Rover 25 car, registration CA03 XDD, which the gang used to escape, was found on fire in Wharfedale Place in the Otley Road area of Harrogate.
Police said the first raid on the Woodlands BP filling station in Wetherby Road in Harrogate had been "well planned and "well organised".
A gang of three, wearing balaclavas and dark coloured clothing and armed with weapons including a crowbar and a knife carried out the raid at about 7.20pm on Tuesday.
They threatened staff before escaping with money which was being emptied from a cash machine by security guards.
The three raiders escaped in a black Mazda, which was later found abandoned in nearby Woodlands Close.