Newcastle have threatened to ban fans who cause trouble following the pitch invasion during last week's friendly clash with Darlington.
Magpies officials are currently working with Northumbria Police to identify those involved, while the Football Association is in contact with both clubs over the incident during last Friday night's game. The club revealed on Wednesday it is to restrict sales for away games to season ticket holders and members so that buyers can be held responsible for their actions.
A club statement said: "In the aftermath of Friday's shameful and unsavoury incidents at Darlington, Newcastle United are currently working with Northumbria Police to identify those individuals who were responsible for criminal behaviour during the game."
It added: "The club will not tolerate any kind of criminal or anti-social behaviour from fans at home or away fixtures, and anyone who is identified as being involved in such behaviour may be subject to a club banning order over and above any action taken by the police.
"The club has already received calls from a number of law abiding fans who have provided information which will help identify offenders. This information is being treated in the strictest confidence and will be shared with the police.
"In order to combat any possible trouble at future away fixtures, a new policy will be implemented by the club which will see ticket sales restricted to season ticket holders and members only.
"As such, the buyer will be held accountable for any trouble associated with the purchase/use of a ticket.
"Supporters attending the forthcoming game at Leeds will be reminded in advance of the game of their responsibilities to the club, fellow supporters and the game of football as a whole.
"Newcastle United sincerely hopes that this incident is a one-off never to be repeated again and that as the 2011-12 season unfolds, the good name, fervour and loyalty of its fans will once again be to the fore up and down the country."
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