Guatemala is evacuating tens of thousands of people after the Fuego volcano started spewing ash and lava.
Volcanologists said powerful eruptions were catapulting burning rocks as high as 1,000m (3,280ft) above the crater and lava was flowing down its slopes.
Locals reported how the roaring of the volcano shook windows and roofs in nearby villages.
Experts say the eruption of the Fuego, 50km (31 miles) south-west of Guatemala City, is the biggest since 1999.
Head of Emergency Evacuations Sergio Cabanas told the Associated Press news agency that more than 33,000 people were being evacuated.
Officials from the National Institute of Seismology, Volcanology, Meteorology and Hydrology (Insivumeh) said lava was covering a 7km (4.3-mile) area on the south and south-western side of the Fuego.
The authorities recommended that air traffic controllers suspend flights in the vicinity of the volcano, as the ash cloud emanating from its crater was spreading quickly.
The 3,760m-tall (12,336ft) Fuego is one of Central America’s most active volcanoes, according to the Smithsonian Institute’s Global Volcanism Program.