During a special operation launched from March 31, the police have arrested 398 riders for riding the motorcycles under the influence of liquor, Police Spokesman DIG Ajith Rohana said today. He said the operation was launched to ensure the security and safety of the riders and pillion riders. In total, 13,320 cases of unsafe motorcycle riding have been reported. Apart from those arrested for drunk riding, 108 have been arrested for speeding, 1,977 for not wearing helmets and 1,303 for violation of licenses.