"It's a river of lava that overflowed its banks and affected the Rodeo village".
Officials said the dead were so far all concentrated in three towns: El Rodeo, Alotenango and San Miguel los Lotes.
The eruption forced the Guatemala City's La Aurora global airport to shut down its only runway.
Ash fell on the Guatemala City area as well as the departments of Sacatepequez, Chimaltenango and Escuintla, which are in south-central Guatemala around the volcano. The news outlet also said the Guatemalan military was providing help which includes clearing volcanic ash from La Aurora airport's runway.
A volcano southwest of Guatemala's capital has erupted for the second time this year, setting off loud explosions and spewing ash almost four miles into the sky.
The conical Volcan de Fuego reaches an altitude of 12,346ft (3,763 meters) above sea level at its peak.
Workers and guests were evacuated from La Reunion golf club near Antigua as a black cloud of ash rose from just beyond the club's limits.
Explosions are still coming from the volcano, said Eddy Sánchez, director of the National Institute for Seismology, Vulcanology, Meteorology and Hydrology of Guatemala known as INSIVUMEH. "Where we saw the lava fall, we ran to a hillside" to escape, she added.
Officials have advised citizens to wear masks due to falling ash, which has been raining down in four of Guatemala's administrative regions.