At just before 9am on Friday (13/11), two vehicles, a black Volkswagen Tiguan and a white BMW, were involved in a collision on Lower Road.
A 28-year-old woman in the Volkswagen and a 23-year-old man from the BMW both sustained serious leg injuries, including broken femurs and pelvis injuries.
They were both taken to the John Radcliffe Hospital in Oxford, where they remain at this time.
No arrests have been made.
Investigating officer PC Craig Ridgley of the Joint Operations Unit for Roads Policing, based at Bicester, said: “This was a serious collision which has resulted in two people requiring hospital treatment.
“I am appealing to anybody who was driving in the area of Lower Road at around the time of the collision and witnessed what happened to please get in touch with police.
“If you have dash-cam installed in your vehicles, I would ask you to please check this and contact police if it has captured anything that can assist this investigation.
“You can do so by making a report online, or by calling the 24-hour non-emergency number 101, quoting reference number 43200374057.”