Patna, May 25 : The Congress in Bihar has appointed new district chiefs and a majority of them belong to the upper castes. Upper castes are considered to be the BJP traditional voters in Bihar, and the Congress' move is to intrude into this core vote bank, said sources. The list was issued from the office of the Congress national general secretary, K.C. Venugopal on Wednesday. The party has appointed 12 district presidents belonging to the Bhumihar caste, eight from Brahmins and six Rajputs. With this, 26 out of the 38 districts of Bihar have upper caste leaders in the Congress party. The party has given five posts to Muslims, four to the Yadav community and three are Dalits. Sources said that this could be a plan of Bihar Chief Minister Nitish Kumar to challenge the BJP and cut its vote bank through the parties of his alliance. /IANS