Oba participated in the June–October 1997 civil war on Sassou Nguesso's side and was wounded in the fighting. After Sassou Nguesso's Cobra militia returned him to power in October 1997, Oba was appointed as Minister of the Interior, Security, and Territorial Administration on 2 November 1997. He was the only member of the government who did not stand as a candidate in the May–June 2002 parliamentary election. After the election, in the government named on 18 August 2002, Oba was appointed as Minister of Security and Police.