 The necessary work-force was recruited by specialised recruiting firms (Robert Williams & Co, Bourse du Travail Kasaï..) and was in some cases supported by governmental recruiting offices (Office de Travail-Offitra..).In Katanga the main labour force were seasonal migrant workers from Tanganyika, Angola, North-Rhodesia and after 1926 also from Ruanda-Urundi.In many cases, this huge labour migration effected the rural communities (many farmers left their villages, which resulted in labour shortages in these communities).