Hundreds of teenagers poured into Belfast city centre on Sunday evening, with the PSNI deploying large numbers of officers to manage the crowds.
The News Letter saw a large stream of young people moving into the Castle Street area from the west of the city after around 6pm.
Two of them, and an officer at the scene, told the News Letter that there had been word of a pre-arranged fight circulating on Facebook.
The crowd in Castle Street appeared to number several hundred young people.
Asked what was going on, one teenage boy said there was “meant to be a fight between two wee girls”.
Another, a 16-year-old from the Lenadoon area to the south-west of the city (a few miles away from the city centre), said: “There’s two wee girls fighting. It was all organised by Facebook.”
He said one girl was Catholic and the other Protestant.
Asked why he was there, he said: “Because everybody in the crowd has come down.”
He added: “It’s a bit of craic.”
A police helicopter whirred overhead, and several armoured police cars and many officers in body armour kept watch on the gathering youths.
At one point, hundreds of youngsters began running from Castle Street towards the Royal Avenue part of the city centre.
The police moved several Land Rovers down Castle Street and then on to the edge of Royal Avenue where they watched the crowd with a video camera.
They also stationed Land Rovers at the bottom of Fountain Street.
One officer said the youths had come from “all over Belfast”, and estimated some to be as young as 11.
He too said that a “pre-arranged fight” seemed to lie behind the gathering.
One bystander, a 45-year-old east Belfast man who said he had been heading home at the time, likened the horde of teenagers to “soldier ants”.
“It was literally surreal,” he added.
The News Letter did not witness any fight, or any violence from the youths gathered in the area.
There is no suggestion that anyone pictured above was involved in any trouble.
Not long after 7pm the crowd had largely scattered.
Despite the size of the police operation and the number of teenagers involved, as of 9.15pm, there was no police statement about the incident.
It later emerged that a fight had indeed taken place, with footage of it being posted online. Click here for the subsequent report.