The UN Security Council passed a resolution permitting ONUC to use military force to prevent civil war, make arrests, halt military operations, arrange ceasefires, and deport foreign military personnel. Under the authorisation of this resolution, UN forces launched Operation Rumpunch and Operation Morthor with the aim of securing their own positions in Katanga and eliminating the presence of mercenaries in Élisabethville, the Katangese capital. The former, though limited in scope, was largely successful, but the latter failed to achieve its objectives. As Morthor was underway, Special Representative Conor Cruise O'Brien announced, "The secession of Katanga has ended." This statement was quickly realised to be premature; Katanga fought the offensive to a stalemate.
