Click photo to enlarge
The Nevado del Ruiz volcano spews fumes near Herveo, Colombia, Friday April 6, 2012. Colombia's Geology and Mines Institute has been keeping a close watch on the Nevado del Ruiz volcano since its activity began to increase in February. In 1985, the town of Armero was wiped off the map and thousands of people were killed when the Nevado del Ruiz volcano exploded and set off a series of mudslides.
BOGOTA, Colombia—Authorities in Colombia say a towering volcano is showing renewed activity and could erupt in weeks or days.

Gas and vapor has been rising periodically from the Nevado de Ruiz volcano since February and the country's geology institute says people in some areas are reporting "strong odors of sulfur."

As of Friday, officials have not yet ordered any evacuations around the 17,457-foot (5,321-meter) volcano roughly 90 miles (145 kilometers) west of the country's capital, Bogota.

A 1985 eruption at the volcano brought a river of rocks and mud sweeping across the town of Armero, killing 25,000 people.