Members of the Garda National Drugs Unit are today continuing to arrest the people who sold them drugs over the past six weeks.
Up to 130 people are expected to be arrested and face charges under this seventh phase of "Operation Clean Streets".
The anti-drugs strategy, in which plainclothes gardaí buy drugs on the streets and in pubs and clubs over a period of time, before making mass arrests, has been in operation since 1997. There have been six such operations before this one.
Four men were arrested in morning raids yesterday on homes and other accommodation in the Dublin area and were detained at city-centre Garda stations.
They are being held under the Misuse of Drugs Act. Further arrests were expected through last night.
In this latest operation gardaí have been buying mainly heroin, but also ecstasy, cocaine and cannabis from street dealers over the past six weeks. Though a Garda spokesman would not identify the parts of Dublin where drugs were found to be most easily available, it is understood the areas highlighted were in the south inner-city, Ballyfermot and Clondalkin.
Gardaí in this operation confirmed for the first time that crack cocaine is available on Dublin's streets.
Officers from the GNDU bought three rocks of the instantly addictive drug from a foreign national in the north inner-city for €120.
Drugs have become increasingly available in pubs and night clubs. Eight pubs were targeted.
Although this operation was centred in Dublin, the strategy has been taking place nationwide since June 1999, when almost 200 people were targeted in raids in Dublin as well as counties Louth, Laois, Wexford, Offaly and Westmeath.
In February 2001, 77 "skunk" cannabis plants, each with an estimated street value of £1,000 when mature, were seized in two houses in Westport, Co Mayo.