A Burundian official says a military officer was among four people killed in violence associated with the extended tenure of President Pierre Nkurunziza.

Deputy police spokesman Moise Nkurunziza, who is not related to the president, said Thursday that unknown gunmen ambushed Col. Emmanuel Buzubona as he arrived home on a motorcycle in Bujumbura Wednesday evening

Nkurunziza said the men shot at and threw a grenade at Buzubona, also killing the motorcycle's driver. He said Buzubona was based in Tanzania and had come home for his annual vacation.

Two armed men were shot and killed by the military in the Mugamba commune in the country's south, he added.

President Nkurunziza's controversial third term has set off rounds of political violence in which more than 400 people have died.