A daycare facility and a car were set alight Sunday night in the latest of the incidents, reports news agency NTB.
Both fires were extinguished by Monday morning, operation leader Cathrine Sylju of Oslo Police told the news agency.
Police have been present in the area throughout the weekend after youth set fire to rubbish and threw stones at firefighters, security guards and police, according to the report.
“We think the same gang is out again. It is remarkable that this has happened for the third night in a row, at almost the same place,” Sylju said at 2am on Monday.
“First they set light to some paper on top of a car. Shortly after, we received a report of a fire at a daycare,” the officer continued.
Police dispatched several units to apprehend the youths, but were unable to track them down, reports NTB.
Two teenagers aged 17 and 18 were arrested after a comprehensive police operation on Saturday, accused of dropping 15kg of stones on a security guard's car as it passed under a bridge, according to the news agency.
Politiet har pågrepet 3 personer. De blir anmeldt for ikke å etterkomme pålegg og skadeverk.— OPS Politiet Oslo (@oslopolitiops) May 28, 2017
“We don't know whether it was the same boys or some others from the same gang. There were several of them out on Saturday night that we didn't catch,” Sylju said.
The gang also caused disruption Friday night, with several incidences of rubbish being set on fire in the area. Stones were thrown by youths at security staff, police and fire services responding to reports of the fires.