Eleven Burundi police officers were wounded in a string of overnight grenade attacks on police stations across the capital, Bujumbura, security sources said Saturday.
Witnesses said gunfire and explosions could be heard from 9 p.m. local time (1900 GMT) on Friday and echoed across parts of the capital for several hours.
A police official blamed the attacks on demonstrators opposed to President Pierre Nkurunziza's controversial bid to stand for a third term in elections set for July 15.
Human rights group APRODH says at least 70 people have been killed since late April in protests over Nkurunziza's bid to remain in power.
Opposition activists say Nkurunziza's re-election bid is unconstitutional and a violation of a peace deal that ended civil war. Nkurunziza's supporters say the president was appointed rather than elected to his first term, allowing him to legally seek a third term.
