Guatemala remained on alert after evacuating villages during an eruption of the Fuego volcano, one of Central America’s most active volcanoes. About 1,700 people remained in shelters Tuesday with the evacuations to stay in place until conditions improve. The country’s disaster agency raised the alert level to red in three communities where about 29,000 people are affected by ashfall and schools remain closed. Authorities warn the next 72 hours are critical as mudflows descend from the volcano. Residents were advised to cover their water deposits and use face masks as protection from ash. The eruption started Monday morning, with clouds of gas and ash rising above the volcano as lava and pyroclastic flows rolled down the slopes.