Unidentified gunmen killed four people late on Saturday in two villages southeast of Burundi’s capital Bujumbura.
The gunmen attacked two villages in Mugamba District, 60 kilometres southeast of Bujumbura, and killed four people, Etienne Nijimbere, a local government official said.
Nijimbere added that all four victims were members of President Pierre Nkurunziza’s CNDD-FDD party.
There was no claim of responsibility for the attacks.
Three armed groups, including one led by officers that attempted a coup in May 2015, have launched attacks against Nkurunziza administration, Burundi’s government officials say.
Burundi accuses neighbouring Rwanda of supporting the anti-Nkurunziza armed groups.
However, the international community raised concerns that the violence could spread to whole Great Lakes Region, recalling the 1994 genocide in Rwanda.
The killings are the latest incident in a cycle of violence in land-locked Burundi which has spiralled in since April 2015 when Nkurunziza decided run for a third term, despite a constitutional two-term limit.
More than 400 people have been killed in tit-for-tat attacks between rival armed groups, according to the United Nations and human rights groups.