Police investigating a rollover on Highway 404 that sent three children to hospital.

Four people, including three young children, have been taken to hospital after a single-vehicle rollover on Highway 404 in Markham.

Ontario Provincial Police Sgt. Dan Hunter said a vehicle was travelling north on the highway near Elgin Mills Road East when it crashed into a ditch just before 5 p.m.

He said an adult and three children – an infant, a three-year-old, and a 10-year-old – were injured due to the crash.

One of the children was ejected from the vehicle, Hunter said.

Two of the children were transported to SickKids hospital with non-life-threatening, non-life-altering injuries.

The driver and the 10-year-old were taken to a local hospital.

Hunter said they are investigating if the children's car seats were properly used.

There are road closures in the area as police investigate.

#Hwy404 NB N of Elgin Mills Rd single SUV rollover into E ditch. 2 children transported to Sick Kids, 1 child and adult transported to local hospital in Vaughan. Lane closures in the area during the investigation. No ETA on full reopening just yet. ^dh

— OPP Highway Safety Division (@OPP_HSD) September 4, 2020