The trouble erupted when police were called to deal with a hoax pipe bomb in the Taghnevan area of Lurgan.

Police vehicles were damaged in the violence, which is reported to have involved children as young as 10.

Officers were maintaining a presence in the area on Saturday evening. The SDLP's Dolores Kelly said "sinister elements" were "directing" the trouble.

She urged parents to keep a close eye on their children.

"I would appeal to parents to keep, particularly their young boys, at home," she said.

"At least, know where they are and ensure they are not getting into trouble because some of them are onlookers and it's very easy to get caught up in situations like this or indeed to get hurt.

"There are sinister elements obviously behind this. This doesn't just happen sporadically. There are others who must be directing this. Petrol bombs do not appear out of thin air."

The trouble started at about 1100 GMT on Saturday when police said they were attacked with stones, golf balls and other missiles.

A minibus was hjjacked near the Kilwilkie estate, but it was later retrieved by a community worker.

The police have advised motorists to avoid the Kilwilkie estate, the Antrim Road, North Circular Road and Lake Street.

On Wednesday, the security forces uncovered component parts for a 250lb car bomb in the Antrim Road in Lurgan.

A man has appeared in court in connection with the discovery.