VANCOUVER -- Police in Mount Currie, B.C., say a single-vehicle crash there killed two people Saturday afternoon and sent two more to hospital.

The Stl'atl'imx Tribal Police Service said in a news release that the crash happened around 2 p.m. on Xitolawcw Road, where the vehicle went off the road and flipped over in a ditch.

All of the occupants of the vehicle "are local to the Mt. Currie area Lil'wat community," the police service said in its release.

"The Lil'wat First Nation is a close-knit community," the release continued. "This tragic incident has taken a toll on the heart and spirit of all Lil'wat people and other members of the St'at'imc Nation."

The two passengers who died were a 29-year-old woman and a 27-year-old man, police said in an update Sunday. A 30-year-old woman and a 26-year-old man are in hospital with non-life-threatening injuries, police said.

The driver of the vehicle, a 32-year-old woman, was not seriously hurt in the crash, according to police.

The cause of the crash has not been determined, but police said they are not ruling out speed and alcohol as factors that may have contributed to it.

The tribal police service is investigating, with the help of the Lower Mainland Integrated Collision Analysis and Reconstruction Service, Pemberton RCMP and the BC Coroners Service, police said.

On Saturday, BC Emergency Health Services said paramedics were called to the area of the crash for a report that a vehicle had gone over a cliff.

Three ground ambulances and an air ambulance were dispatched to the scene around 2 p.m., and two people were transported to hospital, according to BC EHS. The police release indicates that the patients are a man and a woman with "unknown injuries."