From Katanga 1960-63: Mercenaries, Spies and the African Nation that Waged War on the World, by Christopher Othen (History Press, 2015), Kindle Loc. ~1797:
Stanleyville was a town of pastel inter-war buildings more suited to the French Riviera than Africa. It was there, after Lumumba’s arrest, that Antoine Gizenga declared himself Prime Minister of the Congo, dismissing Kasa-Vubu and Mobutu as traitors. The Congo now had two rival governments to go with its two secessionist states. Gizenga, a depressed-looking 35-year-old with a mouth like a trout, appealed to the Soviet Union for help.
‘If the imperialists think that we will surrender’, he said, ‘or if they think they will kill off the Congolese people’s liberation movement, they are wrong’.
Soviet premier Nikita Khruschev authorised a $500,000 payment to Pierre Mulele, the Stanleyville representative in Cairo. Spies suggested that Mulele skimmed some cash for himself. The Soviets looked the other way. Gizenga needed money to keep his 6,000-strong version of the ANC loyal.
‘It is clear that if the army does not receive wages it will refuse to fight,’ reported Czech newsman Dushan Provarnik from Stanleyville:
The Gizenga government has to pay its soldiers at least the same money that Mobutu gives his own soldiers, i.e. 2,000–6,000 Congolese francs depending on grade. Under the existing circumstances, when the government has no revenues, as taxes have not been raised, these expenses are a heavy financial burden.
Attempts to supply Gizenga with arms and advisors were less successful. A Czech air bridge from Prague through Egypt failed when Nasser refused access to his airspace. Lumumba’s former confidant Kwame Nkrumah seemed happy to help but somehow Soviet weapons sent via Ghana never reached the Congo. The Ghanaian leader did not reveal he was talking trade treaties with the Americans.