Police were called to a report on Monday of an off-road motorbike being used around the Freeman's Wood area of the Marsh.
They found two men using the scrambler type motorcycle, causing alarm and distress to members of the public and dog walkers.
Police issued the rider of the motorcycle with a section 59 warning of the Police Reform Act 2002, which means if the man or the bike are found riding in an anti-social manner again in the next 12 months they will seize the bike.