The Garda Public Order Unit was sent to back up firefighters in the Cherry Orchard area of west Dublin last night.
Dublin Fire Brigade was dealing with two cars that were set on fire at Orchard Lawns.
A group of young people who had gathered nearby were moved on.
While the scene was preserved for a forensic examination.
Gardaí say no injuries have been reported and no arrests were made.
Local Sinn Féin councillor Daithí Doolan says people are on edge already;
"This trouble only creates more fear for the elderly and vulnerable who are already anxious in these difficult and uncertain times."
He went on to say; "People need to reach out, show solidarity and support each other. This violence has no place in Cherry Orchard or any community."
