A 13-year-old girl has been stabbed and six teenagers arrested on suspicion of attempted murder.
Humberside Police said she was found at the side of the A63 in Hessle at about 07:00 GMT.
She suffered “lacerations” to her neck, chest and abdomen and her injuries are “life-threatening”, the force said.
Four boys aged 14, 15, 16 and 17, and two girls aged 14 and 15 were soon arrested in a wooded area nearby.
Det Sup Simon Vickers said he believed the attackers “knew the victim”, who is in a critical condition in hospital.
A cordon is in place around the wooded area off Ferriby High Road and there will be a police presence over the weekend, he added.