BOGOTA, Colombia – An eruption at the towering Nevado del Ruiz volcano has forced the closure of a regional airport in western Colombia.
Colombia's Geological Service says bursts of ash rose nearly a mile and a half (2,300 meters) above the peak of the volcano at about 5:50 a.m. (6:50 a.m. EDT; 1050 GMT).
A somewhat smaller eruption three hours earlier prompted closure of the La Nubia airport in Manizales, capital of Caldas state.
The 17,457-foot (5,321 meter) volcano has been under close observation since a 1985 eruption killed some 25,000 people and demolished the town of Armero.
Seismologists say earth tremors indicate movement of magma within the volcano's system.