"When police and emergency services arrived to put out the fire, we were met by around 50 young people throwing stones," police duty officer Ronnie Dahlqvist told the TT news agency about Sunday night's altercation.
"One police officer was slightly injured after a rock hit his knee."
The unrest began with several assaults, but ended with the gang of youth nabbing bicycles and other objects to build barricades.
"They threw out bikes and tore down road signs to try to prevent us getting access with our cars," Dahlqvist specified.
Police detained one individual and mooted the rest from the premises. Most of the youngsters - who are now being investigated for inciting a riot and exercising violence against an officer, have been identified.
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"These are gangs that we've had problems with for three years," Dahlqvist said. "More or less every single one that we have identified is someone we've been in contact with before."