A teenager pointed a gun at a dad-of-three who refused him entry to his daughter's 16th birthday party.
Armed gardai rushed to the house in north Dublin after the dad raised the alarm when a group of 50 aggressive teens attempted to join celebrations in the family home.
News of the party leaked out on social media, leading to dozens of teenagers arriving at the door.
During the confrontation, teens clambered over the wall around the family home in Cabra and shouted abuse at the shocked mother and father.
Things turned nasty when the young girl's father refused the gang entry and one boy produced a gun - which later transpired to be a pellet gun.
None of the teens were known to the family - and it was feared that several were very intoxicated.
"I told them 'no way' and it suddenly got very aggressive," the father told the Herald.
"Then this lad pointed what I thought was a gun right at me. I went back into the house and told them I was ringing the guards."
The shaken father said that he thinks teenagers got wind of the sweet 16 party on Facebook.
"I don't know how word spread - it must have got out on Facebook or something," the 43-year-old said.
"The party was going along fine and then suddenly this large group of teens arrived and wanted to get in. There must have been about 50 of them."
Party-goers inside the house were left shocked by what was going on outside both in the garden and on the street.
The gang of teens only dispersed when they heard the sirens of garda patrol cars.
While armed garda units responded to the alert, it later transpired that the weapon involved was most likely a pellet gun. It is believed that several pellets may have been fired at the exterior of the terrified family's home.
The family declined to be identified amid fears they could be subjected to reprisal attacks.
"When you organise a birthday party for your 16-year-old daughter, you just don't expect this kind of thing," the shocked mother added.
Some of the teenagers suspected to have threatened the family are already well known to gardai. Several are suspected to have acted as 'runners' for a local major-league drug dealer who was previously linked to the gang led by slain crime lord Eamon 'The Don' Dunne, who was shot dead in 2010.
The Cabra gangster is suspected of involvement in the non-fatal shooting of a man in the Blanchardstown area last summer and some of his associates are believed to have been involved in the gun murder of Paul Cullen in a pub in Cabra last year.