Police are asking for witnesses to come forward following an early morning collion on highway 9 near Schomberg.

Two vehicles were approaching each other when they crashed head-on.

It took police more than an hour to remove one of the drivers from the wreck. He is in critical condition.

Two others were taken to hospital and one of them has serious injuries.

At this point, police don't know which vehicle crossed over the centre line.

That stretch of highway is expected to remain closed through the morning.