Police are looking for witnesses after two people were killed in a collision north of Toronto on Thursday evening.

York Regional Police say they were called to the single vehicle collision around 5:30 p.m. in Whitchurch-Stouffville, Ont.

They say a car had collided with a tree and the 24-year-old man who was driving the vehicle was pronounced dead at the scene.

Police say the 23-year-old male passenger died in hospital.

Investigators are asking witnesses or anyone else with information on the crash to come forward.