One adult and two juveniles were arrested during Manchester United under-21s' 4-0 whooping of local rivals Manchester City on Tuesday night.
Mike Keegan of the MailOnline reports "an adult male and a juvenile were arrested for assault while another juvenile was arrested for invading the pitch." Greater Manchester Police, who were called by United, now seek CCTV footage provided by the club.
Fighting in the stands occurred as United youngster Ashley Fletcher netted the third with 10 minutes to go, as reported by Keegan. It is reported "punches were thrown" in a "cordoned off area between City supporters in the corner of the Sir Alex Ferguson stand with United fans to their right.