A number of searches connected to investigations into cross-border crime have been taking place in Warrenpoint, County Down, police have said.
Police in the Irish Republic are also undertaking a number of operations, a Garda spokesperson said.
However, they would not specify where the searches are taking place, how many officers are involved or the nature of the crime being investigated.
No arrests are believed to have been made during the searches.
The Assets Recovery Agency is not involved in the operation.