Police have released CCTV of a man they want to speak with in relation to the incident, which happened at 6pm last night.
The 22-year-old victim was filling up her car at Tesco petrol station in Centenary Way when she went to pay at the cashier before walking back to her car.
As she got in the driver’s door, a man, who was in possession of a knife, got into the passenger seat and told her to drive. The victim screamed, got out of the car and ran to the cashier.
The man then left the vehicle and made off on foot along Centenary Way.
DS Paul Barlow, of Burnley CID, said: “This was a frightening incident for the victim who was simply getting back into her car after paying for petrol and an investigation to find the man responsible is under way.
We are keen to speak to the man pictured on the CCTV images in connection with our on-going enquiries and I would urge anyone who recognises him or who has any information about this incident to contact us as soon as possible.”
Anyone with information can contact police on 101 quoting log 1171 of 11th February. Alternatively Crimestoppers can be contacted, anonymously, on 0800 555 111 or online at Crimestoppers-uk.org.