Gardaí searched three cannabis grow houses simultaneously on 21 October 2013 in an operation by the Garda National Drugs Unit, Operation Nitrogen, targeting cannabis cultivation.[1] At Unit 6B on the Clash Industrial Estate in Tralee, County Kerry, officers found a large cultivation operation with about 1,800 plants valued at €1.3 million and detained two Vietnamese men, one of whom was injured jumping from the building’s roof while trying to escape and was taken to hospital.[1][2] The Kerry divisional drugs unit led the Tralee raid.[2]

Officers also searched a converted house at Falty, Oldtown, Athlone, County Roscommon, where a Chinese man in his late 20s was arrested and drugs valued at €240,000 were seized, and a house with sheds at Carrigaloon, Virginia, County Cavan, where 700 plants valued at €560,000 were recovered and a Chinese man in his 50s was arrested.[1] In total the three searches yielded cannabis plants valued at about €2.1 million, with four men detained under drug-trafficking legislation.[1]