Two teenagers and a younger boy received serious injuries after a collision in the heart of Caroline Springs this afternoon.

Witnesses told Star Weekly that a truck and Subaru Liberty with P plates collided at the intersection of Caroline Springs Boulevard and Commercial Road about 4pm.

One witness said she was in the McDonalds restaurant when she heard the bang and soon saw people on the road tending to the injured on the road.

Southbound traffic on Caroline Springs Boulevard is being detoured via Commercial Road. One northbound lane is open and there are significant traffic delays in the area.

An Ambulance Victoria spokeswoman said five people were assessed at the scene.

Two teenage boys were taken to the Royal Melbourne Hospital in a stable condition and one primary school ages boy was taken to the Royal Children’s Hospital with minor injuries.

He remains in hospital on Friday in a stable condition.

All victims suffered from upper body pain, most likely as a result of injuries suffered from their seatbelt.