Oxford United fans who halted the game against Mansfield by invading the pitch are facing a three-year ban from domestic and international matches.

Nottinghamshire Police are investigating incidents that occurred towards the end of Saturday's game at Mansfield Town.

Both clubs could also face punishment from the Football Association, which is expected to launch its own inquiry into the trouble.

A small number of Oxford United fans caused a five-minute hold-up towards the end of the fixture, which the U's lost 1-0. CCTV footage, eyewitness accounts and photographs are being used to help the police.

Two Oxford United fans were arrested, and club chairman Nick Merry warned them that they face bans if convicted.

He also said any further trouble could force the club to review its decison not to have a routine police presence at home matches, a move which would prove costly.

A club statement said yesterday: "We will take the strongest possible action against fans found guilty of entering the field of play.

"This is a criminal offence and can lead to a three-year ban from both domestic and international matches. The club can also issue bans at their discretion."

Mr Merry said: "We do not need the sort of incident that we saw on Saturday. There were a number of families and children who were very scared by what was going on around them, and that is totally unacceptable.

"Anyone found guilty has no right to call themselves a supporter of Oxford United.

"Because of the excellent general behaviour of our fans we rarely have a police presence at home matches, but incidents like this jeopardise that situation and could cost us a considerable amount. The message is simple get behind the team, but do it the right way."

Tony Ashley, the club's safety officer, said a decision would be made about policing for Saturday's home game with Chester City following talks with Thames Valley Police.

Trouble started at the Mansfield match after a glass bottle was thrown from outside the ground into the Oxford fans and hit a young boy.

Several dozen Oxford fans were involved in confrontations with stewards and at least two ran onto the pitch.

Adam Stuart Broadbent, 24, of Blenheim Court, Oxford, has been arrested and charged by Nottinghamshire Police with going on the playing area of the football pitch.

He was bailed to appear before Mansfield magistrates on Friday.

A second Oxford fan was also arrested for a pitch incursion, but was released without charge on police bail until April 20.

A 27-year-old Mansfield man was arrested and later released without charge.