Three teenagers have been arrested after one allegedly swung a knife at a police officer Friday night and was pepper sprayed, NT Police say.

Acting Commander Sachin Sharma said the alleged knife-wielding teen was later found to have another knife in his pocket along with a bag of cannabis.

Police said in a statement that they responded to a disturbance caused by a group of teens gathering in Mitchell Street.

Details around the nature of the disturbance were not provided. It was also unclear what injuries the officer suffered.

It said officers attempted to disperse the group when a 19-year-old teenager allegedly pulled a knife from his shorts and begun swinging it at a police officer.

The officer pepper sprayed the teenager causing him to drop the knife to the ground.

He was immediately arrested along with the other two teens who were charged with disorderly conduct.

The knife-wielder was taken to Darwin Watch House and faces multiple charges for assaulting a member of the police force, disorderly behaviour in a public place, possessing or carrying or using a controlled weapon at night and possession of cannabis for personal use.

He is scheduled to appear in court today. 

Act Com Sharma said: “Last week we had a number of our members assaulted while trying to conduct their policing duties. Our members deserve the right to not be assaulted while we are engaged in protecting and serving the NT communities”.

Assaults on police or emergency workers carry maximum penalties of imprisonment of 16 years according to section 189A of the Criminal Code Act 1983.

The Northern Territory Police Association earlier called for an urgent introduction of mandatory minimum sentencing for offenders found guilty of assaulting police or emergency service workers in the wake of recent attacks on police officers.