Guatemala's National Disaster Reduction Coordination (CONRED) office declared an orange alert on Friday after the Fuego Volcano, some 45 km from Guatemala City, erupted and triggered waves of small earthquakes.
According to reports reaching here, the eruption spewed ash 500 meters into the air, and triggered 20 to 30 small earthquakes a minute.
The warning affects more than 31,000 people living in 14 nearby towns in the provinces of Escuintla, Sacatepequez and Chimaltenango.
Disaster reduction personnel are monitoring radios and coordinating with local government officials, and they said the citizens were at no risk for the moment.
However, local mayors have prepared plans to evacuate citizens to emergency hostels if the situation worsens.
According to vulcanologists, eruption records of Fuego Volcano, one of the country's most active volcanoes, date back to 1542, and at its fiercest it could spray ash all the way to El Salvador or Honduras.
CONRED recommended the country's civil aviation authorities take precautions in the area.