An elderly man is seriously ill in hospital after being knocked down by a motorcyclist in Lincolnshire.
The rider was also knocked to the ground, but then got back on his bike and rode off without offering assistance.
The victim, 75-year-old Alec Jennings from Grimsby, was walking along Horncastle Road, in Bardney, on Saturday afternoon.
Police believe the biker lost control and collided with Mr Jennings.
The motorcyclist was wearing yellow leathers with red markings and was riding with two other motorcyclists.
His bike was thought to be a Yamaha and its number plate may have started with W.
Lincolnshire Police described the incident as a "callous crime".
Mr Jennings suffered broken bones but his condition is described as stable.