The P.S.N.I. has castigated a large group of young people, some of whom were wearing masks, when they launched an attack on a rival school in Northern Ireland on Wednesday evening.
The incident occurred inside the grounds of Campbell College in east Belfast.
It is not known what school the young people involved in the attack attend.
The group responsible launched eggs and flour at statues contained within the grounds of the school and they also attacked the entrance to the school.
The P.S.N.I. dispatched three Local Policing Teams (L.P.T.), one Tactical Support Group (T.S.G.) and one P.S.N.I. dog handler.
T.S.G.s specialise in counter-terrorism, search operations, method entry, marine response, enhanced medical aid scenarios, high risk escorts, chemical, biological, radiological and nuclear incidents, close protection, roads policing, mutual aid and public order.
"This is believed to be linked to a rivalry between schools," said the P.S.N.I.
"I just want to take this opportunity to make sure that you are all aware, that yes, throwing eggs at property is criminal damage, yes you are committing an offence, yes you will be dealt with by police and yes you could get a criminal record as a result.
"I know you think it’s a bit of a laugh, a bit of craic and it’s harmless.
"However, just have a think about your career prospects when you have a conviction or caution for a criminal offence."
The P.S.N.I. condemned the incident as it left some local residents feeling scared.
"Also, think about the residents who were boarding at the school who you frightened the life out of.
Not to mention the three L.P.T. call-signs, a T.S.G. call-sign and a police dog handler you had running about the place to sort you out!
"Just take a minute to stop, think and wise up.
"There will be follow up enquiries tomorrow and suspects will be dealt with."