A 17-year-old youth has been arrested in connection with an assault on two teenagers in Derby.
Two 13-year-old boys were attacked as they walked to catch a bus home following the finish of their after-school studies, Derbyshire Police said.
CCTV showing the two victims being punched and kicked on the evening of December 8 was released by the force on Monday.
Detective Inspector Brian Bilby said: "Although we have a suspect in custody this does not mean the investigation stops and we would still urge anyone who has information to contact us.
"The youth will be questioned by detectives while we continue with our inquiries."
Anyone with information is asked to call police on 101.