Police in Gibraltar have banned Spanish motorcyclists from entering the Rock amid plans to carry out a cross - border demonstration over the land dispute between Spain and the UK.On Monday, Royal Gibraltar Police said the planned protest on September 21 “will be stopped at frontier,” to which they say has made people “anxious.” The group of motorcyclists seeks to promote “international attention” and awareness about the heritage of Gibraltar by selling t-shirts that bear the Spanish flag and proclaim sovereignty over the territory. Tensions between Britain and Spain have escalated in recent weeks over the latter’s introduction of new strict border controls for Gibraltarians trying to enter Spain. The new controls have led to delays of several hours at Spain-Gibraltar border for commuters. The 6.8-square-kilometer British territory says Spain’s border checks are in retaliation for the creation of an artificial reef in the nearby waters by Gibraltar government that has negatively affected Spanish fishermen. The territory, Britain seized from Spain in 1713, remains a bone of contention between the two European countries.