Police are investigating a serious crash in East Vancouver that left seven people in hospital Friday morning, two of whom suffered life-threatening injuries.

Authorities said a black Mercedes SUV and a grey Ford Focus collided head-on on Grandview Highway near Penticton Street shortly before 6 a.m.

There were four people in the Mercedes and three in the Ford, and all of them had to be taken to hospital.

The 20-year-old Burnaby man behind the wheel of the Ford and a 19-year-old female passenger both have life-threatening injuries. A third person who was in the sedan has serious injuries, but is expected to survive.

A 54-year-old Richmond man was driving the Mercedes. He and three passengers aged 48, 59 and 70 all suffered "relatively minor injuries," police said.

It's unclear what caused the crash, but police temporarily closed the highway between Nanaimo and Slocan streets so officers from the Collision Investigation Unit could examine the scene.

Grandview is expected to remain closed until about 4 p.m. Friday.

Anyone who may have witnessed the collision is asked to call authorities at 604-717-3012.