Several polling centres were attacked during the night in Burundi's capital Bujumbura and in some provinces ahead of controversial parliamentary and local elections, but the attackers failed to damage the electoral materials, police said Monday morning.

Polls opened in Burundi Monday in an extremely tense climate punctuated by violence, after weeks of unrest sparked by President Pierre Nkurunziza's announcement that he would seek a third term, which his opponents deem unconstitutional.