Two women suffered serious head injuries when they were struck by a motorcycle as they crossed a road in Warrington town centre.
Both women, from Lymm, were taken to Warrington hospital after the collision in Brick Street on Thursday night.
One of the women, a 22-year-old, was transferred to Walton Hospital where her condition is described as critical.
Police arrested the 23-year-old rider of the Kawasaki, who was uninjured, on suspicion of dangerous driving.
He was later released on bail pending further inquiries.
The other injured woman, aged 18, suffered head and spinal injuries and remains in a serious but not life threatening condition.