The Philippine government has turned down a request to hand over 38 men to face charges over recent fighting with Malaysian forces in Sabah.
The men, followers of Jamalul Kiram III the self-styled Sultan of Sulu, were rounded up by Philippine authorities off the coast of Tawi-Tawi province earlier this month.
They are believed to have been among at least 200 Filipino fighters who landed and laid claim to Sabah about a month ago, sparking deadly clashes in which at least 70 people died.
"They cannot be turned over. We have no extradition treaty with them [Malaysia]," Defense Secretary Voltaire Gazmin said on Tuesday.
"There should be a mutually agreed arrangement with their government. Malaysian laws will prevail in their area. On our part, we will apply our laws."
Malaysian authorities, meanwhile, have filed charges of terrorism against eight members of Kiram's “Royal Sultanate Army.”
Authorities in Sabah have also announced that at least 42 of the 116 people detained on suspicion of having links with Kiram in Malaysia have been released.