JOHANNESBURG — Angolans voted on Wednesday in an election in which the defense minister is the front-runner to succeed President José Eduardo dos Santos, who will step down after 38 years in power in an oil-rich country troubled by widespread poverty and corruption.

About 9.3 million Angolans were registered to vote for the 220-member National Assembly; the winning party will then select the president. The president’s chosen successor is João Lourenço, the defense minister and a former governor who fought in the war against Portuguese colonial rule as well as the long civil war that ended in 2002.

Minor flaws in the voting process included delays in the opening of some polling stations, especially in remote areas, said André da Silva Neto, the president of the election commission.

Angolan rights activists say that the governing party, the Popular Movement for the Liberation of Angola, or MPLA, unfairly used the machinery of the state ahead of the election, noting that most news media coverage focused on the MPLA campaign. Opposition parties have said there were irregularities ahead of the voting.