A man and a teenage girl have been arrested allegedly for selling a hand grenade in Sydney's inner-west. Police have alleged the 20-year-old Menai man and 17-year-old girl from Earlwood sold a hand grenade at Tempe last night. Officers attached to Strike Force Calderon, made up of police from Task Force Gain and Newtown Local Area Command, arrested the pair a short time later at Newtown. The grenade was secured in Gough Whitlam Park in Earlwood and the area sealed off. The Police Bomb Squad made the grenade safe before handing it over to army bomb disposal officers. The man and teenage girl were taken to Newtown police station for questioning and charged with unauthorised possession of prohibited weapons and unauthorised sale of a prohibited weapon. The man was refused bail and is expected to appear in Parramatta Bail Court today. The girl was also refused bail and is expected to appear in Cobham Children's Court today. Task Force Gain commander Detective Superintendent Mark Henney said the police operation and arrests were not related to any investigation by Strike Force Seta, the police arm set up this week to deal with Sydney's recent race-related violence.