A Burundi official says four members of the country's ruling party have been killed in an attack in continuing violence associated with the extended tenure of President Pierre Nkurunziza.

Jerome Ntakarutimana, the local chief of the Mugamba district in Buriri province said Sunday that the attack targeted supporters of the ruling party who had gathered for an exercise to clean up the environment.

A survivor of the attack, who insisted on anonymity for his safety, said the four men died after armed men dressed in hoods and military fatigues stormed a bar Saturday night. The attack increases the death toll of people killed in the past week to 10.

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