The woman passenger suffered a suspected broken pelvis while the male passenger sustained seat belt injuries.
Meanwhile, the driver of the other vehicle involved – a Citroen C4 – sustained serious injuries and was taken to Dorset County Hospital in Dorchester. His injuries are not thought to be life-threatening.
A Dorset Police spokesman said: “Anyone who witnessed the collision or saw the vehicles prior to the collision are being asked to call Dorset Police on 101, quoting incident 407.”
•A steady stream of shocked well-wishers placed floral tributes at the crash site yesterday and words of condolence were posted on social media websites.
One tribute at the scene, from Sammy, said: “I cannot believe this has happened. You will be missed by so many people. Take care up there. Sleep tight.”
Another simply stated: “Ben, we will never forget you. Hugs and kisses.”
• The 19-year-old Citroen driver, from Blandford, has been arrested on suspicion of motoring offences and released on bail.