EUFOR did not confirm the identity of the apartment owner, but local media reports say neighbours said the flat belonged to former Bosnian Serb soldier suspected of sheltering top war crimes fugitive Ratko Mladic.
Mladic, along with former Bosnian Serb president Radovan Karadzic, was indicted for genocide in 1995, and both men have been on the run ever since.
EUFOR and NATO both work in support of the ICTY, conducting operations to help capture war crimes suspects and targeting those who support them.
Under their new operation, dubbed Oak Tree, each case relating to the capture of a suspected war criminal will be assigned a team and allocated resources to meet the particular needs of that case.
EUFOR has also said that for security reasons, the force will not discuss current operations related to war crimes suspects, or persons suspected of supporting them.
Rade Mutic, a spokesman Banja Luka’s Centre for Public Safety, has said that this is an international operation with little local involvement.
"The operations conducted by EUFOR are EUFOR’s and NATO’s business - they are undertaking this independently,” he was quoted as saying in a report by Serbian radio station B92.
This lack of cooperation suggests international forces are distrustful of domestic security services, which - while voicing support for the tribunal - have had poor results in delivering top fugitives, such as Karadzic and Mladic, to The Hague.
A statement released by EUFOR has warned Bosnia that failure to cooperate with the operation to capture war crimes suspects could hamper its future chances of joining the EU.
At a press conference held in The Hague on August 16, spokesman for the prosecutor, Anton Nikiforov, denied raids in Banja Luka came about as a result of a tip off from the tribunal.
He added that even though EUFOR did coordinate their efforts with the prosecution, the action appears to be targeting mainly the network of supporters of the fugitives.