At least two policemen were injured during a grenade attack in Burundi's capital on Wednesday, witnesses said, as the country awaited results from Monday's parliamentary election which was boycotted by the opposition, Reuters reported. Sporadic gunfire could also be heard in several other flashpoint districts in Bujumbura, marring celebrations marking the independence day holiday in the former Belgian colony in east Africa. Burundi has been locked in its worst political crisis since its civil war ended a decade ago, with protests erupting in late April against President Pierre Nkurunziza's bid to seek a third term in office. The presidential vote is due on July 15.