An elite Irish army unit has stormed a Panamanian cargo ship suspected of carrying significant amounts of drugs in a major operation off the south-east coast of Ireland.

Members of the highly-trained Army Ranger Wing descended by fast-rope from a helicopter on to the ship, which became the focus point of a multi-agency operation which began on Sunday.

The co-ordinated response from the Irish Naval Service and Army Ranger Wing also involved customs officers and the Irish police’s national drugs and organised crime unit

The agencies said the seized MV Matthew is a Panamanian-registered bulk cargo vessel originating in South America.

It was intercepted by the Army Ranger Wing and detained in the early hours of Tuesday.

The agencies said a “significant quantity” of suspected drugs were found on board the cargo ship.

The Army Ranger Wing boarded the ship after the Naval Service’s patrol vessel, the LE William Butler Yeats, fired warning shots in its direction.

Two helicopters and two planes were also involved in the operation.

The Irish Air Corps and Naval Service had been tracking the container ship over a number of days.

In a statement, the Defence Forces said: “A specialist team from the Army Ranger Wing (ARW) then deployed by helicopter on to the MV Matthew via fast rope insertion in challenging conditions.”

After the ship was made safe, the Garda units (Irish police) and customs officers boarded the vessel alongside the naval service.

The naval service escorted the ship to an Irish port where it will be detained for a detailed search and investigation.

Crowds of people lined the walls of Cobh harbour as the cargo ship was transported to a naval base on Haulbowline in Co Cork.

The cargo vessel will now be the subject of a detailed examination by Revenue Customs and An Garda Siochana

Armed members of the Ranger Wing were seen on board alongside the ship’s crew members and other Defence Forces personnel.

Three men, aged 60, 50 and 31, have been arrested on suspicion of organised crime offences and are detained at garda stations in Wexford.

In a joint statement, Revenue and An Garda Siochana said: “The cargo vessel will now be the subject of a detailed examination by Revenue Customs and An Garda Siochana.”

The operation was conducted in collaboration with the Maritime Analysis and Operations Centre – Narcotics (MAOC N) based in Lisbon, Portugal, and partners from the National Crime Agency (NCA), the Drugs Enforcement Agency (DEA) and French customs service DNRED.

The Chief of Staff of the Defence Forces commended the efforts of all personnel involved in the operation.

Lieutenant General Sean Clancy said: “I would like to personally commend the courage, discipline and professionalism of all personnel involved in this successful operation.”

He said the multi-agency operation demonstrates the interoperability of the Defence Forces, underlining the “unique capability that we bring to the defence of the State”.

He added: “The significant intelligence-led planning by the joint task force enabled the co-ordination and execution of this complex multiagency operation.

“This operation demonstrated the importance of all services of the Defence Forces and their ability to operate in the most challenging of conditions.”

Minister for Justice Helen McEntee congratulated the State and international bodies involved in the operation.

She said the drugs on board would have “no doubt been destined for Irish and European markets”.

In a statement she said: “It will represent a blow to the organised-crime gangs involved in drug distribution internationally.”

She said it shows the success of An Garda Siochana in building coalitions to tackle transnational crime.

“Illegal drug distribution and misuse does untold damage to our communities. Criminals may seek to overcome the barrier of borders, but as shown today borders are not barriers to effective criminal co-operation.

“Tackling organised crime is a key priority for Government and is central to building safer, stronger communities. We will always provide An Garda Siochana with the support and resources they need.”

The major multi-agency operation followed an alert after a separate boat ran aground off the east coast.

The Irish Coast Guard said it received a distress call from a vessel in difficulty off the coast of Co Wexford at about 10.10pm on Sunday.

Waterford-based coast guard helicopter R117, and Rosslare RNLI were sent to the scene where a fishing vessel was aground on a sandbank off the coast of Blackwater, Co Wexford.

After attempts to tow the vessel were unsuccessful, the people aboard were successfully winched from the vessel.

Both R117 and the Rosslare RNLI were subsequently stood down.