Four persons were killed and 29 people injured Sunday night in Bujumbura and towns to the north in grenade attacks.
The police said on Monday that a grenade attack on a bar in Ngozi town north of Bujumbura killed four people and wounded 27, while a blast in the northern town of Kirundo near a bank injured two people.
Police spokesman Pierre Nkurikiye said a grenade attack in the Musaga district of Bujumbura also wounded one police officer, he said.
Parliamentary elections are due in the crisis-hit country on 29 June, Senate 24 July while Presidential election is due on July 15.
President Pierre Nkurunziza’s decision to contest for a third term has triggered a wave of protests, an attempted coup d’etat and an exodus of refugees across the country’s borders.