Demonstrators in Ouagadougou, Burkina Faso, on Thursday after a coup was announced.Credit...Theo Renaut/Associated Press OUAGADOUGOU, Burkina Faso — Military officers overthrew the government of Burkina Faso on Thursday, plunging the West African country into chaos and violence, while the leader of the country’s transitional parliament denounced the coup and declared himself the interim president.