Patrols are continuing following the incident at Commercial Road, Pill, at about 20:35 BST on Thursday.
A 16-year-old boy, a 20-year-old man and a 17-year-old girl were arrested for breaching a dispersal order to tackle anti-social behaviour.
Two 13-year-old boys and a 24-year-old man were also arrested on suspicion of violent disorder.
Police and fire crews attended the scene, and the incident was over by 23:00. Officers said no one was injured.
Newport city council leader Debbie Wilcox has called a meeting on Monday with police and fire services to discuss the incident, saying residents' safety was a "priority" and the "negative actions of a small group of people will not be tolerated".
Gwent police local policing commander Glyn Fernquest said: "We are taking this incident extremely seriously.
"I want to send a warning to anyone intent on causing trouble that you will be arrested."
Six people have been arrested after reports of disorder in Newport.