The two people who died following the collision on the A1104 at Snape Hill, Saleby, near Alford on Good Friday have been named by police.
70-year-old Jean Thomas, of Jacklin Crescent in Mablethorpe, died at the scene and 16-year-old Matthew Ellis of Bunkers Hill in Lincoln has since died in hospital.
Jean Thomas was a front seat passenger in a red Ford C-Max, which was involved in a collision with a white Mercedes van and a black Vauxhall Corsa. Matthew Ellis was a passenger in the Corsa, and died at Hull Royal Infirmary on Saturday evening.
The driver of the Ford C-Max, a 72-year-old man from Mablethorpe is in a serious condition at Queens Medical Centre in Nottingham. A rear seat passenger in the same car, an 11-year-old boy thought to be from Birmingham, is in a serious condition in Hull Royal Infirmary and another rear seat passenger, whose age is not known, is also in a serious condition in Hull Royal Infirmary.
The driver of the black Corsa, a 17-year-old man from Lincoln, is in a serious condition in Hull Royal Infirmary.
Two further passengers in the Corsa, both 17 years old and from Lincoln, suffered serious injuries and were taken to hospital in Boston and Grimsby.
The driver of the White Mercedes van, a 50-year-old man from Boston was not injured.
Anyone who was in the area of the A1104 at Snape Hill near Alford and saw the collision itself or saw either the black Vauxhall Corsa or the red Ford C-Max prior to the collision is asked to contact the police on the 101 number or the witness hotline on 01522 558855.