Guatamala's Pacaya volcano erupted early Thursday, sending volcanic material more than 400 meters in the air, authorities said.
The Institute of Vulcanology warned that the eruption could intensify with ash rising as high as 1,000 to 2,000 meters, posing a threat to air traffic at Guatemala's international airport.
"Ash could spread over Guatemala City due to the direction of the wind," the country's disaster response office said in a statement.
The last major eruption of Pacaya in May 2010 claimed the life of a television journalist, drove thousands of people from their home, and forced the closure of the Guatemala City airport for five days.
The 8,373-foot (2,552 meter) high Pacaya is 50 kilometers (30 miles) south of the capital. It is one of three active volcanoes in Guatemala.
Explore further: The Gulf Stream kept going during the last Ice Age