Media playback is unsupported on your device Media caption Rioting in Lurgan has been described by the police as an orchestrated, intense and prolonged violent attack.

A gunshot was fired at police during serious disorder linked to a security alert in County Armagh on Sunday night.

More than 100 petrol bombs were thrown at officers on Lake Street in Lurgan.

The Police Service of Northern Ireland (PSNI) said officers were on the receiving end of "orchestrated, intense and prolonged violence".

The alert ended on Monday evening when two "suspicious objects" found close to a railway line by police were declared to be hoaxes.

Image copyright Pacemaker Image caption The PSNI said the cost of their operation could run into "tens of thousands of pounds"

The attack happened while police were searching for the objects.

Police said a crowd involved in the disorder remained in the area until the early hours of Monday morning.

No-one was injured, but a number of police vehicles were damaged.

The railway line was closed for much of the day, and reopened early on Monday evening.

Media playback is unsupported on your device Media caption Rioters threw petrol bombs at police in Lurgan, as this video posted on YouTube shows

Supt David Moore said: "The behaviour of those involved in the disorder was nothing short of disgusting.

"At one point, a gunman emerged from the crowd and fired at least one shot at police. Mercifully no one was hurt.

"We are extremely fortunate not to be talking about officers being seriously injured while trying to do their job.

"I am grateful to the officers who were on duty last night for their professionalism and resilience and for the contribution they make to keeping this community safe in extremely challenging circumstances."

Media playback is unsupported on your device Media caption Supt David Moore blamed dissident republicans for the disorder

Supt Moore said there had been a number of "completely irregular" reports that an object had been found on the railway line on Sunday morning.

He said police officers had received assistance from the Army as part of the security operation.

He said the cost of the operation, which involved police helicopters and tactical support groups, would run into "thousands, if not tens of thousands of extra expenditure".

He added: "The officers who were standing there last night, absorbing petrol bombs, bricks and at one stage live ammunition, ought not to be there.

Image copyright Pacemaker Image caption Officers were on the receiving end of "orchestrated, intense and prolonged violence", the PSNI said

"They ought to be chasing down burglars, chasing domestic abuse victims, keeping our roads safe."

Supt Moore compared those behind the attacks to so-called Islamic State militants, saying: "They have nothing to offer but destruction in their own communities."

He said "the work of dissident republicans is very evident", adding that their intention was to "provoke serious violence".

Supt Moore described the demographic of those involved in the rioting as "young easily influenced men, and bewildered old men who haven't realised that the world has moved on".

Image copyright Pacemaker Image caption An operation to dispose of the device is causing rail and traffic disruption in the area

The operation caused a number of homes to be evacuated.

Passengers on the Belfast to Dublin train service had to be bussed between Belfast and Newry in County Down.

Public transport provider Translink is advising passengers to check its website for travel updates.