The outgoing UNICEF representative in Burundi says this past week’s attack on a school in the capital, Bujumbura, is a senseless tragedy.

On his last day of service, Johannes Wedenig told VOA Saturday the grenade attack on the Day of the African Child school, which wounded a 15-year-old boy, “is a deplorable assault on a place that should always be safe for every child.”

UNICEF said the ongoing political unrest in Burundi should not get in the way of protecting children, who “have been killed, detained, and continue to be at great risk.”

Also Saturday, security sources said 11 Burundi police officers were wounded in a string of overnight grenade attacks on police stations across Bujumbura.

A police official blamed the attacks on demonstrators opposed to President Pierre Nkurunziza’s controversial bid for a third term.

Human rights group Aprodeh said at least 70 people have been killed since late April in protests over Nkurunziza’s bid to remain in power.

The election is set for July 15.

Opposition activists said Nkurunziza’s re-election bid was unconstitutional and a violation of a peace deal that ended civil war.

Nkurunziza’s supporters said the president was appointed rather than elected to his first term, allowing him to legally seek a third term.