Guatemala's Fuego volcano has erupted, spewing smoke and ash 3km into the sky and forcing the evacuation of thousands of people as lava oozed down its slopes, local emergency services said.
The volcano, 40km southwest of the capital Guatemala City, erupted on Thursday afternoon (local time), belching a cloud of ash above the crater, Guatemala's emergency agency CONRED said in a statement.
Roughly 11,000 people have been evacuated and 8000 more were awaiting transfer to shelters, said Sergio Cabanas, CONRED's director of emergency response. Up to 10,000 others could be moved to safety depending on wind conditions and ash emissions, he added.
"For the moment, the strength (of the eruption) has not calmed," Cabanas said.
Two lava flows, about 600 meters long, were heading down the sides of the volcano accompanied by pyroclastic flows of hot rock and ash, CONRED said.
"The greater danger right now is the ash," Cabanas said. If the lava flows continue to spread, he said, it would hinder the evacuation process.
Speaking at a press conference during a state visit to Costa Rica, Guatemalan President Otto Perez Molina said the eruption could affect people as far away as Guatemala City.
"It is a shame, but this is a fact of life in our country, so we will do the best we can to avoid people being harmed," he said.
The airport remains open but airport officials shut down the air approach route between Guatemala City's La Aurora airport and Tapachula International Airport in Chiapas, Mexico.
"For the moment, we are urging caution because of the changing winds near the volcano, mainly from the east and southeast," civil aviation spokeswoman Oddra Lacs said.
Witnesses said the explosion darkened skies and prompted the closure of schools and universities.
"It is almost impossible to see the volcano because lots of ash is falling," said Ricardo Castillo, a 23-year-old Guatemalan English teacher at the Del Valle University in Santa Lucia, about 16 miles (25 km) from the base of the volcano.
"There are lots of clouds and the sky is very dark. Classes have been canceled and the students are very scared, hearing the volcano and seeing the ash cloud."
The Fuego volcano last erupted in May. A 2010 eruption at Pacaya, one of Guatemala's four active volcanoes, covered Guatemala City with a layer of ash, closed the airport and forced the evacuation of hundreds of families.