A pair of police officers were assaulted as they tried to control a large group of anti-social youths in west Fife.
Three teenagers have been charged in connection with the violent incident, which left the officers shocked but not seriously injured.
The 16-year-old boys were were also arrested in connection with public order offences and a report will be submitted to the Children’s Reporter.
Police said the assaults followed a spate of “unacceptable” anti-social behaviour in Inverkeithing, which prompted several calls from the public.
They warned any repeat of the disorder would be dealt with robustly to protect local people and officers.
Locals reported seeing a group of up to 40 or 50 teenagers gathered near Prestonhill Quarry and later at a bus stop in Hillfield Road on Friday evening and police responded at around 10.30pm.
Local community sergeant Kenny Bow said calls about nuisance behaviour in the area had risen recently.
He said: “We recognise that anti-social behaviour can be a huge source of distress within our communities.
“Over the past month, we have seen an increase in the number of calls reporting nuisance and disruptive behaviour in the Inverkeithing and High Valleyfield areas.
“Although we are committed to working hard with our partners and the public to prevent disorder, we’d appeal to parents and guardians to speak to their children about their activities outside the home.”
He added: “A minority of young people are putting themselves at risk of harm, at risk of obtaining a criminal record and are completely disregarding their communities and the upset this behaviour can cause, especially to those who are elderly or vulnerable.
“The behaviour we experienced on Friday is completely unacceptable and we will make no excuses for dealing with it robustly in order to protect members of the public and our own staff.”
This time last year parents were encouraged to know their children’s whereabouts following fires, underage drinking and disruption at Silver Sands beach in Aberdour.
SNP councillors Alice McGarry and David Barratt said the behaviour appeared to escalate as schools broke off for exam leave.
“It was Silver Sands last year and the police have a plan for the summer but an increase in patrols there means they have displaced,” said Mrs McGarry.
“We’ve seen a rise in this type of behaviour in Inverkeithing over the last few weeks.”
Mr Barratt added: “It’s unfortunate this is still going on but the police are prepared to react to incidents when they happen.”
Anyone with concerns about anti-social behaviour is urged to contact their local policing team on 101 or visit their local police station.
Information about Friday night’s incident should be reported via 101, quoting incident number 4998 of May 24.