Guatemala City's La Aurora international airport temporarily suspended operations on its only runway on Wednesday due to ash after the Pacaya volcano increased activity, a week and half after a violent eruption from another peak killed more than 100.
"This is a preventative measure taken to safeguard the lives of passengers and aircraft safety," Guatemala's civil aviation authority said.
Pacaya, located some 48 kilometers (30 miles) south of the capital, is spewing a column of ash and gas some 3,500 meters (11,483 feet) into the air and has produced different low-level lava flows over the last few months, the seismological, volcanic and meteorological institute Insivumeh said in a statement.
Winds are blowing the column some 10 kilometers (6 miles) to the north, northeast.
Insivumeh asked authorities to prepare for the possibility that Pacaya may increase its volcanic activity over the "coming hours or days."
Guatemalan authorities are already on high alert after the Fuego volcano erupted on June 3, shooting fast-moving currents of ash, lava and super-heated gas down its slopes that buried villages in its path. The eruption of the volcano was its worst in four decades, killing at least 110 people and leaving nearly 200 missing.
Pacaya, one of Guatemala's 34 volcanoes, had its last major eruption in 2010, killing three people and forcing hundreds to evacuate.