Police in the North have arrested four men as part of an ongoing police investigation into internet child pornography.
The arrests followed searches which were carried out over two weeks in relation to 25 people.
During the investigation, the PSNI says residential and business addresses were searched and up to 100 computers and an extensive amount of software, including CDs and DVDs, were seized. They are now being examined by experts.
A PSNI spokeswoman said the four men arrested have now been released, pending further inquiries.
The searches form the second phase of Operation Ore, the major British police probe into online child pornography.
The operation was launched two years ago, after investigators in the US found customers around the world were accessing images of child abuse from a Texas-based site.
Police forces in Britain and the North have since checked over 7,000 individuals.
Of the 3,500 Operation Ore suspects that were arrested, over 1,600 have been charged and more than 1,200 convicted.