KINSHASA, Congo — Voting materials arrived late or sometimes not at all in precincts throughout the country Monday, but Congo’s elections went ahead, raising doubts about the legitimacy of a poll that already has seen at least nine people killed and could drag sub-Saharan Africa’s largest nation back into conflict.

Country experts and opposition leaders had urged the government to delay the vote due to massive logistical problems. There are fears that the Central African nation, whose rain forests are still inhabited by rebel armies, could be plunged into violence again if it is unable to agree on the results of the presidential and legislative election.

Violence over the weekend left at least four people dead, and it continued Monday when gunmen opened fire on a truck transporting ballots in the town of Lubumbashi. That and a subsequent attack by unidentified assailants left five more dead, according to Dikanga Kazadi, the provincial interior minister.