A mother and her baby have been rushed to hospital after a head-on crash following a botched U-turn on a highway in West Gippsland.
Police said the woman, 21, had been attempting to complete a U-turn on the Princes Highway near Darnum about 1.25pm on Sunday.
Her white Ford sedan is believed to have struck a wire barrier, causing her to lose control of the vehicle and collide with an oncoming car.
The woman, from Heyfield, about 80 kilometres away, was taken to the Royal Melbourne Hospital in a serious condition.
Her three-month-old boy sustained abdominal injuries. He was taken to the Royal Children's Hospital, in a stable condition.
Three people from the other vehicle - the 24-year-old male driver and two women, aged 19 and 50 - were also taken to hospital with minor injuries.
Investigators on Monday appealed for witnesses to the crash, particularly those with dash-cam footage.
Anyone with information can call Crime Stoppers on 1800 333 000. Anyone affected by witnessing the collision can call Road Trauma Support Services on 1300 367 797.