A 17-year-old boy was being quizzed after three people were injured in a hit-and-run during a protest in Armagh.
The youth was arrested when shortly before 10pm a black Renault Megane collided with a number of people in the Newry Road area of the city before fleeing the scene.
Police said three males who were hit by the car sustained non-life threatening injuries.
The teenager was arrested a short time later in the Cavancaw Road area.
People had been protesting in the Newry Road area over the Union flag row.
An hour earlier the Cuhulainn bar on Thomas Street had its windows smashed and fireworks were thrown inside.
Sinn Féin councillor Roy McCartney said:”These very easily could have set fire to the bar or injured those inside.
“The protests, intimidation and violence needs to end and Unionist politicians need to be to the fore, using whatever influence they have, in ensuring this happens.”
SDLP Armagh Councillor Thomas O’Hanlon appealed for calm in the city following the incidents.
“There was a protest on the main Newry Road at the top of the city mall and it caused much disruption to many local people trying to go about their daily business,” Cllr O’Hanlon said.
“The SDLP has continually called for the protests to stop immediately. Where were these protestors when the council was protesting against hospital closures a few years ago? We need to get away from protesting about a flag and start to tackle the issues that really matter to people in Armagh.
“I’m glad there were no injuries tonight after fireworks were thrown into a bar on Thomas Street.
“Those responsible need to take a hard look at themselves and judge how their actions have helped any cause or perceived injustice.
“I appeal for calm and no retaliation to this incident. The key issue needs to be respect. Everyone needs to remember that.”
Police have appealed for witnesses for both incidents to contact them.