Dangerous and anti-social house parties in Belfast's Holyland student district will not be tolerated, the health minister has said.
Footage showing groups of young people congregating and drinking in the area of terraced housing near Queen's University was "deplorable", Robin Swann said.
Coronavirus restrictions in Belfast became legally enforceable by police today and repeat offenders face fines of up to £960.
The minister said: "It is important that we take swift action because the scenes from last night demand it."
A special group including Stormont ministers, police and senior public health experts is meeting to consider their next move.
Local residents in the Holyland, known as such because the names of its streets are drawn from the Middle East, have expressed alarm that people congregating ahead of the new academic term could cause a spike in infection.
Police have stepped up patrols but until now had limited power to intervene.
"The message must go out loud and clear that dangerous anti-social behaviour will not be tolerated," Mr Swann said.
"We are on a knife edge. The new regulations are an attempt to strike the right balance."
Queen's University and Ulster University have said wrongdoers will be subjected to disciplinary processes and added that strong messages had been conveyed to all new admissions.
Mr Swann said the actions were deplorable but did not represent all students or young people.
"The Holyland situation does require urgent and co-ordinated action by the authorities, city council and universities."
A new ministerial-led group on enforcing Covid regulations has been established.
The new university term begins later this month.
Mr Swann said he was disappointed by house parties being held in Belfast last night.
"I do not think they represent young people across Northern Ireland who have made sacrifices themselves," he said.
"I do not want young people to be the scapegoats for the increase in Covid-19 in Northern Ireland.
"The scenes last night were deplorable."
Fines will begin at £60 and could go up to £960 for repeat offending.
The minister said: "If you can afford up to £960 for a simple house party and standing in front of someone's garden, I would use that as a caution and a deterrent."
The limits on social interaction between households in the Belfast council area, Ballymena town and postcode areas BT43, BT28 and BT29 were agreed by ministers last week and are now enacted in law.
Postcode areas may be added and removed from the local restrictions as patterns of infection change and further interventions and restrictions can be introduced as necessary.
Limited exceptions include childcare provision and households that have formed a social bubble with another.
No more than six people, from no more than two households, are allowed to meet in private gardens.
People have also been given guidance discouraging non-essential journeys outside the affected zones.
An interactive map has been designed to try and help make the postcodes covered more easily understandable.
There have been two further deaths from Covid-19 reported in Northern Ireland, the Department of Health said today.
There have been 129 new confirmed cases of the virus, making it 641 in the last seven days.
Today's health briefing at Parliament Buildings in Belfast also heard from a senior emergency department nurse at the Ulster Hospital.
Roisin Devlin issued a plea to the general public not to become complacent as she warned of the risk of a second wave over the winter months.
"I know we're all weary of Covid and there are some who feel that this pandemic isn't a big threat but never in my career have I seen colleagues so concerned about the incoming winter," she said.
"We have no agenda; we're simply worried for our patients."
Ms Devlin said increased infection numbers were starting to translate into a rise in hospital admissions.
"If we don't get a hold on the numbers going up at this time, then we'll absolutely at that stage start to see the second wave," she said.
The nurse added: "If we get a second surge with an overwhelming number of very unwell patients, that's going to be exceptionally challenging to us."
The executive's chief scientific adviser Professor Ian Young said infection rates were being kept under review to establish if localised actions were needed elsewhere.
"Certainly I can't exclude the possibility that the Executive might consider that there are other areas where local restrictions are required," he said.
