Six people were hit by plastic bullets after rioting broke out and shots were fired at police on a loyalist housing estate in Co Down last night.
The violence broke out on the Clandeboye Road in the Kilcooley area of Bangor.
Tensions had risen on the estate after police carried out raids against serious crime in the North Down area associated with the Ulster Defence Association. It is believed they were looking for drugs.
Petrol bombs, fireworks, stones and other missiles were thrown at police by a mob of up to 200 people.
At least one car was also set alight and ten police vehicles were damaged. A PSNI spokesman said one police vehicle was hit by bullets.
Calm was eventually restored at around 12.30am. No police officers were injured and the PSNI said they had no reports of any other injuries. No arrests have been made.
The North's Deputy First Minister Martin McGuinness today called on the UDA to de-escalate tensions within its community. He said last night's disturbances were "utterly disgraceful" and should be "unreservedly condemned" by everyone.
"I think it is quite clear from the way in which events moved forward that it was organised," the Sinn Fein MLA said. "So there is a responsibility here on the UDA to recognise that this is unacceptable behaviour and that they have a responsibility to de-escalate situations that may occur within society."
Minister for Foreign Affairs Dermot Ahern said the PSNI had the Government's support in tackling drugs.