Three Asian men have been arrested and another is receiving medical attention after cannabis seizures worth €2.1 million in counties Kerry, Cavan and Roscommon.

Two Vietnamese men were in an industrial unit in Tralee in Co Kerry when gardaí searched the premises and found 1,800 cannabis plants worth around €1.3m.

One of the men was injured when he jumped from the roof of the building in an attempt to escape.

He is being treated at Kerry General Hospital. The other man is being questioned at Tralee Garda Station.

Gardaí said the industrial unit had been professionally converted into a cannabis growhouse.

Elsewhere, 700 cannabis plants worth around €560,000 were found in a house in Virginia in Co Cavan.

A Chinese man in his 50s was arrested and taken to Bailieboro Garda Station for questioning.

In the third seizure, a Chinese man in his 20s was arrested after a cannabis growhouse was discovered in a house in Falty in Co Roscommon.

The drugs have an estimated street value of €200,000.

The man is being questioned at Roscommon Garda Station.

The seizures and arrests were part of Operation Nitrogen, which is an operation by the Garda National Drugs Unit targeting the cultivation of cannabis.