An 18-year-old man arrested by detectives investigating a road traffic collision on Victoria Road in Derry on Tuesday has been released on bail pending further police inquiries.
A 67-year-old woman injured in the collision remains in hospital.
The woman was taken to hospital from the scene of the accident and was assessed as being in a critical condition.
The two vehicle crash happened at around 7.30pm.
The woman is believed to have been the driver of one of the cars.
Her passenger, a 35-year-old man was also taken to hospital at the time with non-life threatening injuries.
Inspector Colin Reeves is appealing for witnesses to the collision: “Investigating officers can be contacted by calling 101, quoting reference number 1046 27/06/17.”
The road remains closed through until Wednesday morning.