The eruption created massive columns of smoke that could be seen from the capital, some 75 kilometers (46 miles) away.
"This type of eruption is stronger than normal and hasn't been seen in recent years. That's why we have declared an orange alert" in the area around the volcano, in western Guatemala, Gustavo Chigna, of the Vulcanology Institute, told local media.
He added that the strong explosion had buried in ash several villages near the 3,763-meter (12,345-foot) tall volcano. Rumblings were heard for several kilometers (miles) around.
Alejandro Maldonado, the head of Guatemala's disaster prevention agency, said 1,500 families had been moved out of their homes and taken to temporary housing.
The agency said in a statement that ash had spread up to 12 kilometers (seven miles) to the west and northwest of the volcano.