Police have been attacked with rocks, slingshots and spears twice in two days in separate Aboriginal communities east of Darwin.
Two police officers were holed up in a building on Millingimbi in east Arnhem Island on Tuesday night while locals threw large rocks at them and badly damaged police cars and a building.
On Wednesday police were attacked by Alyangula locals in eight cars at Groote Eylandt airport when officers went there with drug detector dogs after being tipped off that cannabis was incoming on a plane, NT Police commander Tony Fuller said.
Those police and airport employees had to run for safety on to the airfield as more cars were damaged.
No-one has yet been arrested at Alyangula and while five youths had been arrested at Millingimbi there was a risk that the tension could flare up again, he said.
"We are not sure what the cause of that outbreak of violence was at Millingimbi ," he told reporters.
"There was a pretty dangerous cat-and-mouse game with police, with community members firing slingshots at police, bombarding the property, with large rocks."
However tension had been building for several weeks at Alyangula with local drug users directing "animosity" towards police dogs that had been intercepting cannabis supplies to the island.
"There was a group of eight to 10 vehicles that proceeded to skid around in front of the police causing large dust clouds and there was information that spears and rocks were produced," Commander Fuller said.
"A number of rocks were thrown at police and the employees there at the airport so they retreated behind the wire on to the airfield and as a result additional resources were dispatched.
"Drugs have been an issue on Groote Eylandt and throughout the communities for a long, long time."
The Anindilyakwa Land Council and East Arnhem Regional Council were contacted for comment.
Five male youths aged 12 to 19 were arrested in Millingimbi after a meeting in which the community had been very supportive, Commander Fuller said.
Police were also working with the Anindilyakwa Land Council and other government stakeholders if members were attacked then those responsible would be arrested, he said.
Extra police have been sent to both communities and no injuries have been reported.
Northern Territory Police Association president Paul McCue called for an increase in sentencing as a deterrence, following multiple attacks including at Alice Springs in the last week.