After Lumumba was killed, the US began funding Mobutu in order to secure him against the separatists and opposition. Many of Lumumba's supporters went east and formed the Free Republic of the Congo with its capital in Stanleyville in opposition to Mobutu's government. Eventually, the government in Stanleyville agreed to rejoin with the Leopoldville government under the latter's rule, however in 1963, Lumumba supporters formed another separate government in the east of the country and launched the Simba rebellion. The rebellion had support from the Soviet Union and many other countries in the Eastern Bloc. In November 1964, the U.S. and Belgium launched Operation Dragon Rouge to rescue hostages taken by Simba rebels in Stanleyville. The operation was a success and expelled the Simba rebels from the city, leaving them in disarray. The Simbas were ultimately defeated the following year by the Congolese army.