Three cannabis factories with plants reckoned to be worth more than two million euro have been raided by gardai.
A grow house with about 1,800 plants was found during a planned search of a premises on an industrial estate in Clash, Tralee, Co Kerry.
Two Vietnamese men, believed to be in their late 20s or early 30s, were arrested over the seizure, estimated to be 1.3 million euro.
Gardai said one of the suspects was injured when he jumped from the roof of the building in an attempt to escape and is being held in Tralee General Hospital, while the other is being questioned at Tralee Garda station.
A house at Falty in Oldtown, Athlone, Co Roscommon, was also searched as part of Operation Nitrogen, an operation by the Garda National Drugs Unit (GNDU).
Gardai said a Chinese man in his 20s was arrested at the property, which had been converted for use as a cannabis growing facility.
The total value of the drugs seized at this location, subject to analysis, was 240,000 euro.
At the same time a house and sheds at Carrigaloon, Virginia, Co Cavan, was also raised and a large cannabis cultivation operation was discovered inside.
A Garda spokesman said 700 cannabis plants, worth about 560,000 euro, were recovered and one Chinese male in his 50s was arrested.
"The total value of the cannabis plants seized over the course of the three searches is approximately 2.1 million euro," he said.
"There was three suspects arrested and are currently being detained under Section 2 of the Criminal Justice (Drug Trafficking) Act 1996 in Tralee, Roscommon and Bailieboro Garda Stations respectively.
"An additional suspect is currently receiving medical attention at Tralee General Hospital."