Five men have been arrested as part of an investigation by the Organised Crime Unit into an illegal debt collection operation.
Detectives believe that two builders hired criminals to force people who owed them large sums of money to repay their debts.
Gardaí have discovered that serious threats were made against some individuals and one of their cars was burned out.
The men are aged between 28 and 77. None of them are registered debt collectors.
Armed officers from the Organised Crime Unit searched six homes in Killester, Raheny, Kildare, Leixlip and Ratoath. One of the homes raided was that of a major drug dealer.
The five men can be held for up to three days.
Two are being questioned in Dún Laoghaire, two in Blackrock and the fifth in Dundrum.
The investigation also involved gardaí from the Dublin Eastern Division and has been ongoing for the past few months.
