As part of ongoing Garda operations to counter dissident republican activates in the border area, an operation was undertaken on Monday, in Drogheda, Castlebellingham and Navan.
During the course of the operation a man, aged 49 years and a woman, aged 43 years, were arrested at Castlebellingham and detained at Drogheda Garda Station.
A short time later, a man aged 30 years was arrested in Navan and is currently detained at Navan Garda Station.
On Tuesday morning a fourth arrest was made in Navan, a man aged 38 years and he too is currently detained at Navan Garda Station.
As part of the operation a commercial premises in Navan was searched along with three residences in Drogheda, Navan and Castlebellingham.
A number of vehicles were also seized for the purpose of search and technical examination.
So far, a 9mm hand gun has been recovered. The operation and investigation is ongoing at this time.
The 43 year old woman detained at Drogheda Garda has since been released without charge.
The operation involved officers from Louth Division, Northern Regional Support Unit, Crime and Security Branch and the Special Detective Unit.