PETROL bombs and missiles were thrown at police, two officers were injured and two 15-year-old boys were arrested after violence broke out in Lurgan.
Violence erupted a few hours after an Apprentice Boys' parade through the Co Armagh town on Monday afternoon.
A small group of men surrounded a PSNI Land Rover and fought officers in the Kilwilkie estate.
Several petrol bombs were thrown at officers during the clashes.
Two policemen took cover behind a Land Rover as people threw missiles at them. One man was later seen apparently attempting to pull an officer from the vehicle.
A police spokesman said the two officers' injuries were not thought to be serious.
Two 15-year-old boys were arrested for offences including riotous behaviour and criminal damage.
A burnt wheelie bin was also dragged onto railway tracks close to the Kilwilkie estate.
A policeman came under fire from a masked youth who threw stones as the officer grabbed the bin and dragged it off the tracks.
The railway line was closed on Monday afternoon for the second time in 24 hours and services between Belfast and Dublin were disrupted.
Superintendent David Moore said: "I would appeal to parents and those within the local community to exert their influence to bring this senseless behaviour to an end".
Earlier, more than 60 loyalist bands took part in the Apprentice Boys' parade through the town from 11.30am.
Ulster Unionist MLA Jo-Anne Dobson said the "respectful" behaviour of the Apprentice Boys and bands "stood in stark contrast to Republicans clearly wedded to violence and who were involved in the vehicle hijacking and petrol bombings earlier in the day and further disturbances later in the afternoon".
"Those who seek to do nothing but take us back to the past should have no place in Lurgan's future,
"I urge the PSNI to take strong action against those who came with the intention of causing disruption and threatening the lives of police officers."
The chairman of the Police Federation for Northern Ireland, Mark Lindsay, said attacks on officers were "wholly unacceptable".
"Those throwing petrol bombs and engaging in minor street disturbances think they are advancing some cause but the reality is they have nothing but empty rhetoric and outdated slogans to offer," he said.
"The officers who were hurt today don't deserve this type of cowardly treatment.
"They are the same as the people they are trying to safeguard, and it is up to the entire community to stand up and say that this will no longer be tolerated."
