A series of violent assaults, a brawl involving 80 people and a knife attack has sparked a three-night public social disorder declaration on Monday for parts of the town from 10pm to 6am.
A three-week, town-centre curfew in March only applied to people under the age of 18.
Chief Minister Eva Lawler said the curfew would act as a "pressure-relief valve" and improve community safety.
Northern Territory Chief Minister Eva Lawler said the violence had to stop. (Darren England/AAP PHOTOS)
"I love Alice Springs but the offending and behaviour we have seen over the last 96 hours will not be tolerated," she told reporters.
"The curfew will provide police extra powers to get on top of the situation."
Commissioner Michael Murphy said a series of crimes across the weekend had led to the decision to impose the curfew.
These included a brawl involving about 80 people in which police were assaulted, a knife attack on a 42-year-old woman, the robbery of a service station and the assault of four off-duty police officers on a street.
"The intent of this declaration is to disrupt the behaviours associated with the harm we're seeing in Alice Spring," he said.
"It applies to all classes of people - it will apply to adults and it will apply to youths."
The curfew will be imposed on the town centre between Anzac Hill, the Alice Springs Hospital, the Stuart Highway and Leichhardt Terrace, which runs along the Todd River.
New laws give police the powers to lock down parts of Alice Springs. (Aaron Bunch/AAP PHOTOS)
"Anyone coming into the zone can be engaged by police and they can be asked to leave or alternatively they can be asked to stay, if there is another disturbance, for their own safety," Mr Murphy said.
"A failure to abide in a request by police can lead to an offence and it can lead to an infringement notice or an arrest."
People with legitimate business in the area, such as work or attending an event, and those seeking safety or medical treatment will be permitted to enter the zone.
It comes as NAIDOC week celebrations kick off in the town of about 25,000, attracting about 5000 visitors from the NT, Western Australia and South Australia.
Mr Murphy said police would not disturb the annual event and the curfew would help keep those celebrating safe.
"I'm very aware it's a really important week for the territory and Australia," he said.
NT Police Commissioner Michael Murphy says the curfew will not affect NAIDOC celebrations. (Neve Brissenden/AAP PHOTOS)
The emergency declaration has been made using laws passed by the territory parliament in May that let the police commissioner impose a three-day curfew that can be extended to seven days if the police minister approves.
During the curfew, police can order groups of people to disperse or hold them in an area to prevent maintain public safety.
Swinburne criminology expert Joel McGregor said the NT's crime issues required long-term behaviour change, not-short interventions. 
"While the NT curfew may be stopping crimes being perpetuated during the evening, it should not be thought of as a solution to the problems the (territory) is facing," he said.
The lock down follows a three-week curfew banning anyone under 18 from the town's centre between 6pm and 6am following a series of wild brawls in March.
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