Drinking alcohol in the street and gathering in groups has been banned in an area of Newport following a large-scale disorder.
The city's council unanimously voted for a public space protection order (PSPO) for Pill after youths targeted police with fireworks in November.
Anyone causing a nuisance or disturbance now faces a fine of up to £1,000 through the courts.
Police can also issue fixed penalty notices of up to £100.
The order also includes possessing, selling or supplying intoxicating substance such as so-called legal highs and powers for police to disperse groups of three or more people if they are causing trouble.
A breach of the order is a criminal offence.
Lauran Buchanan Smith is a former councillor of Pill.
She said the city has become a "disgrace from one end to the other" and that she was "ashamed of it".
"I thought Friar's Walk would have made a difference here, but it hasn't," she said.
Civil liberty and human rights campaigners said powers afforded by orders such as PSPOs were too broad and could target the most vulnerable people in society.
Lara Ten Caten, a lawyer for Liberty, said people's ideas of what causes trouble were different.
"If you ask five people what causing trouble means, they are probably going to come up with five different answers."
She said the order could end up "criminalising young people, who for example do not have money to socialise in a pub."
Cabinet member for licensing and regulation, Ray Truman, said: "This PSPO will benefit the neighbourhood of Pillgwenlly and residents will feel more secure knowing that the police can disperse gangs of people and confiscate alcohol if necessary."
Insp Paul Davies from Gwent Police said: "This order is one of a range of measures that can be used to educate and, if necessary, prosecute the minority of persons who cause offence."