Four teenage girls were trapped inside a disused barn with burning blocks of polystyrene, police in Northern Ireland said.
There were no reports of serious injuries and only minor damage was caused to the property at Mount Eagles Avenue in Dunmurry on Monday.
PSNI detective sergeant Hollie McCartan said it was reported that the girls, all aged 13, gained access to the shed.
This was a terrifying ordeal for the girls trapped inside and if they had not managed to contact the authorities the consequences could have been devastatingHollie McCartan
She added: “When inside, a number of male youths set blocks of polystyrene on fire and threw them into the barn.
“Wood and stones were also thrown into the premises which trapped the girls inside.”
They managed to contact Northern Ireland Fire & Rescue Service, whose members attended and rescued them.
Ms McCartan added: “It is extremely fortunate that we are not dealing with more tragic circumstances following this incident.
“This was a terrifying ordeal for the girls trapped inside and if they had not managed to contact the authorities the consequences could have been devastating.
“The persons responsible showed a complete disregard for the safety and wellbeing of those inside.”
One of the suspects involved was described as having blond hair which was shaved at the sides and wearing a black top and navy bottoms.
Another was described as wearing a green and white coloured top, with a third described as wearing a grey tracksuit with the hood covering his face.
Alliance West Belfast representative Donnamarie Higgins said: “I am in utter shock over this incident and find it hard to believe someone, much less young people, could do something which could have easily led to serious tragedy.
“This can only be seen as an attempt to at least injure these girls, if not more.”