Police are looking for a gang of youths who were verbally aggressive and threw items at people and police officers who attended a major annual festival in Gorleston.
The disorderly behaviour happened during the Gorleston Clifftop Festival near the event's fairground.
A Norfolk police spokesman said: 'A large group of youths have been verbally aggressive and thrown items at members of the public and officers.
'Police are keen to hear from anyone who was in the area at the time and may have witnessed it or has mobile footage of the incident.'
The incident happened at about 9.30pm on Saturday, July 29.
It is estimated 20,000 people attended the festival, which is in its 20th year.
Anyone with information on the youths's action at the festival should contact PC Richard Bladon from Gorleston Police Station on 101.
Alternatively people can contact Crimestoppers anonymously on 0800 555 111.
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