 Lumumba and Kasa-Vubu were denied use of Élisabethville's airstrip the following day and returned to the capital, only to be accosted by fleeing Belgians.They sent a protest of the Belgian deployment to the United Nations, requesting that they withdraw and be replaced by an international peacekeeping force.The UN Security Council passed United Nations Security Council Resolution 143, calling for immediate removal of Belgian forces and establishment of the United Nations Operation in the Congo (ONUC).