Irish police detected some 50 people attempting to enter Ireland from the UK illegally last week.
An Garda Siochana said they were refused leave to land and were returned to the UK across four days of action.
The force said officers conducted 11 days of action in quarter four of 2023, and up to May 20, a further 10 days of action had taken place. Across that period, 107 people had been detected without the correct visas or identity papers.
They said four additional days of action took place on the week commencing May 20, when a further 50 people were detected without the correct visas or identity papers.
“During these operations, persons entering Ireland illegally and were refused leave to land (RLTL) and returned to the UK by ferry from Dublin Port to Holyhead or returned to Belfast, as appropriate depending on the individual circumstances,” they said.
In a statement, gardai said officers carry out immigration checks along the border on a regular basis to detect breaches of immigration legislation and detect abuses of the Common Travel Area (CTA).
These include checkpoints on roads and checks on the train line through Co Louth, close to the border with Northern Ireland.
Gardai said they have “significant operational co-operation with the UK Border Force, UK policing services and the Police Service of Northern Ireland, supported organisationally by the Cross Border Joint Action Task Force”.
“Our Immigration officers work in close collaboration with personnel operating buses and trains in the area,” they added.
“A human rights-based approach is adopted in relation to every individual stopped. Immigration officers will clearly identify themselves to all passengers on buses or trains.
“All Garda members have completed training in the Garda Code of Ethics and the Garda Decision Making Model. All checks carried out are lawful, objective and respectful.”