Policemen stand guard outside the area closed due to the eruption of Poas Volcano in the province of Alajuela, Costa Rica, on April 14, 2017. Just two days after suddenly erupting with enough force to leave a crack in the dome of its crater, Costa Rica's Poas Volcano on Friday spewed a plume of smoke and ash more than three kilometers into the air. (Xinhua/Esteban DATO)
