A quarrel between a Saudi national and a Bangladeshi worker in an amusement park here Sunday led to a bloody and violent melee in which 12 people were injured. Security teams rushed to the scene and disengaged the fighting groups. Security authorities have referred the case to Al-Faisalia Police Station. Several ambulances carried the injured to Ar'ar Central Hospital under tight security, Col. Bandar Attallah Al-Ayda, spokesperson of Northern Frontier Region Police, said.