Policemen walk after they fire tear gas canisters at protesters during a protest against Burundi President Pierre Nkurunziza and his bid for a third term in Bujumbura, Burundi, May 21, 2015.

Tear gas at a protest against Burundi President Pierre Nkurunziza and his bid for a third term in Bujumbura, Burundi, May 21, 2015.
© 2015 Goran Tomasevic/Reuters