Newcastle have condemned the "shameful'' behaviour of supporters who invaded the pitch during the team's 2-0 pre-season friendly win at Darlington, with three fans arrested and another escorted from the ground.
Newcastle say they will take "the strongest possible action'' against fans responsible for causing a 10-minute delay in the match as celebrations of Sammy Ameobi's 55th-minute goal turned ugly.
The match looked in danger of being called off as scenes turned violent at the Darlington Arena and, although calm was eventually restored, the guilty parties can expect repercussions.
A statement from the club's managing director Derek Llambias read: "On behalf of everyone at Newcastle United FC, we wholly condemn the behaviour of a number of our supporters who invaded the pitch during the second half of the club's friendly against Darlington this evening (July 15).
"The club will be seeking to obtain footage of the disorder from Darlington FC and the police and will be taking the strongest possible action against those individuals responsible for the shameful behaviour.
"This behaviour is not typical of the vast majority of our fans, however this incident gives a poor impression of Newcastle United and its loyal supporters.''
Hatem Ben Arfa made his first appearance since his horror leg break at Manchester City last October as Newcastle boss Alan Pardew named a strong line-up for the team's first pre-season game.
Captain Joey Barton, who will miss the tour of North America after being denied a visa, opened the scoring in the third minute when he knocked home a cross from Leon Best before substitute Ameobi drilled home a fine shot 10 minutes into the second half.
Durham Police confirmed three visiting Newcastle fans were arrested for "pitch incursion'' and another was escorted from the ground.
A 22-year-old man, a 21-year-old and a 17-year-old were detained.
Durham Police said the 21-year-old, who is from Newcastle, was charged with going onto a play area and disorder. The 22-year-old, who is from Gateshead, was charged with going onto a play area and a public order offence.
Both men will appear before Darlington Magistrates Court on July 26.
The 17-year-old youth was charged with going onto a play area and will appear at Darlington Youth Court on August 5.
Manager Alan Pardew reportedly intervened to try to calm fans down and appeal for them to clear the pitch.
Some of the 9,000-plus crowd thought the match had been abandoned but the referee managed to restart the game after the playing surface was cleared.
Police could not confirm reports of an isolated outbreak of fighting between fans during the match.
A force spokeswoman said: "There has been a crowd of more than 9,700, which is significantly more than expected based on ticket sales. Everything was peaceful until Newcastle scored their second goal and a pitch incursion occurred which was high spirited but not violent.
"A further pitch incursion of around 20 to 30 people followed - a Newcastle supporter being escorted from the ground and three Newcastle supporters were arrested for pitch incursion.
"The game ended without incident and crowds have subsequently dispersed.''
She said the three people remained in custody.
Pardew was disappointed the trouble marred a decent display by his side. He said: "Having reflected overnight on yesterday's match at Darlington that was interrupted in the second half by the actions of some of our supporters, I am left bitterly disappointed by the events that unfolded after Sammy Ameobi scored our second goal.
"Apart from the frustrating disruption to what was a very good game of football and an important part of our pre-season preparation, the pitch invasion was totally unacceptable and has brought shame on everyone connected with Newcastle United.
"We came to play a football match and to provide entertainment for a family audience - instead we witnessed some truly appalling behaviour which damages the reputation of this great club and the vast majority of our true and law-abiding supporters.
"As (managing director) Derek Llambias said yesterday evening, the club will now be taking the strongest possible action against those individuals responsible and that can't happen soon enough. I speak for everyone at Newcastle United when I say I never wish to see those scenes at a football match again.''