Two women have been arrested and two potential victims of human trafficking rescued after a number of searches in greater Belfast.
The operation, on Thursday, was part of a joint investigation being carried out by the PSNI and police in Sweden.
A spokesperson said officers from both countries have been working together on Operation Burgrave for months.
They said it was targeting a crime group suspected of controlling prostitution and human trafficking.
Swedish police have obtained European arrest warrants for the suspects and, subject to court approval, they will be flown to Stockholm to face charges there.
The suspects, aged 27 and 20, are due to appear at Belfast Crown Court later on Friday.