INNISFIL, Ont. - A 20-year-old man from Newmarket was killed and four people were injured following a head-on collision Tuesday evening in Innisfil.

South Simcoe police say they believe a southbound car driven by the man crossed the centre line (on 10 Sideroad) and hit a northbound car just before 7 p.m.

The unidentified man was pronounced dead at the scene.

The four injured people -- two passengers in the man's car and a 40-year-old Innisfil woman and her teenage daughter in the other car -- suffered non-life threatening injuries.

Police say speed is believed to have been a factor in the crash.