Parents stockpiling cheap booze are unwittingly contributing to drink-fuelled violence among teenagers, according to police.
Youths are sneaking alcohol unnoticed from their own homes as adults take advantage of cut-price supermarket offers.
Officers have no control over drink obtained from private houses but have warned parents will be contacted if a teenager is found with alcohol.
Chief Inspector Adrian Annandale said under-age youths in Fife are continuing to abuse alcohol, either buying it from local off-sales or taking it from their parents.
“With the advent of cheap alcohol on sale at supermarkets there is a tendency for parents to bulk buy in large quantities,” the area commander for north-east Fife said.
“As a result, youths taking alcohol from the house tends to go unnoticed.”
He added: “This poses an additional problem as the police can control unauthorised sales from licensed premises but have no control over alcohol obtained from private houses.
“There is clear evidence that when a youth is under the influence of alcohol they are most likely to be a victim of crime or involved in criminality.”
There will be a police crackdown over the winter, with officers on mountain bikes targeting youths gathering in parks and other hard to reach areas under the cover of darkness.
High-visibility patrols will also be stationed at bus stops, where they will confiscate any alcohol before the teenagers have a chance to congregate.
The tactic, known as Operation Shorehead, follows evidence of territorial violence by drunken youths in Levenmouth.
Mr Annandale said: “This level of antisocial behaviour and violence becomes more prominent and increases during the winter months, specifically when the clocks are turned back and the darker nights encroach upon us.
“As an organisation we are alert to this and prepare accordingly.”
He added: “Social media such as Facebook ensure that groups are well organised as they attempt to keep ahead of the police.
“We are alert to this fact and ensure that local open-source intelligence is gained in order to become proactive.
“The intention is deliberate in its approach with regard to the confiscation of alcohol, drugs, licensing enforcement and violence reduction.”
Mr Annandale urged people to take confidence that officers deployed on Operation Shorehead were using “disrupt, detect and deter” tactics to prevent crime.
“The deployment of officers on mountain bikes ensures that we can access areas where they are known to gather and early intervention of high visibility patrols at bus stops as they make their way to gather ensures that alcohol is confiscated.
“Where under-age youths are found in possession of alcohol, their parents are contacted and made aware that they are becoming involved in criminality. They are subsequently returned to the care of their parents.”