Police and residents have been caught up in clashes between rival sectarian teenage gangs.
Many were said to be unaware of which part of Belfast they were in with police reporting some teenagers were dropped off at the interface by parents.
Youths threw stones, rocks and weights at police and cars as officers moved in to break up a pre-arranged fight at an interface.
Police said they believed it was the latest in a spate of gatherings arranged by young people across the city on Facebook.
And with brighter evenings and milder weather conditions in the coming weeks, there are concerns of an increase in the confrontations as well as illegal raves.
Police were called to the Alliance area of north Belfast on Thursday night after youths from both sides of the community confronted one another.
It took officers more than two hours to disperse the crowd, some of whom began to attack police with missiles when they were prevented from getting to each other.
A police sergeant in north Belfast said: "Whenever the young people on the Alliance/Jamaica side realised they couldn't get across to the Alliance/Deerpark side, they decided to throw stones, rocks and weights at cars on their own side, and then at us when we intervened.
"Several cars of local people on Alliance were damaged and we took some hits as well.
"No injuries thankfully, but some, and I emphasise some, young people need to take some responsibility for themselves and their own community. In particular, the amount of young girls who didn't appear to even know what area they were in concerns me greatly. The details of seven young people were taken."
He added on Facebook: "Finally, and almost unbelievably, we had reports that some of the young people had been dropped off at the interface by their parents in cars."
Last month one of the largest pre-planned fights witnessed by police to date took place, when around 100 youths gathered in Belfast city centre.
Several teenagers were arrested and others cautioned after officers disrupted youths gathering to fight at around 10.30pm in the city's main shopping area.
A vehicle was damaged as the crowds went through Cornmarket and out to Castle Place. Two males, aged 15 and 16, were arrested on suspicion of riotous behaviour and criminal damage. The previous evening two girls, aged 14 and 15, were cautioned following reports of a planned fight.
Weeks earlier 300 teenagers gathered in a public park for a party arranged on Facebook.
Officers from the PSNI's Tactical Support Group were involved in moving the young people from Belfast's Cave Hill Country Park.
Police said many of those in attendance were "heavily intoxicated" and had travelled from across the city.