The volcano, located some 120 kilometres south of Quito, covered surrounding towns with a blanket of ash over the weekend. Clouds of sulfuric gases have burst from the volcano's crater over the past days, and at night the sky glows red from the magma surfacing at the crater.

Experts said the volcano, some 5,020-metres above sea level, had an 80 percent chance of erupting.

If the Tungurahua does erupt some 25,000 people could be directly affected, a scientist at the country's geophysical institute said Tuesday. A hydro-electric plant that produces 10 percent of the country's energy is also at risk, the scientist said. In Banos, barely ten policeofficers and soldiers patrolled the streets to prevent criminals from taking over. The area has been quiet since Saturday, when an "orange alert" was issued after a notable increase in the volcano's activity.

The orange alert was an upgrade from the yellow alert that had been in effect since last month. A red alert is reserved for an actual eruption.Banos, known as the `Port to the Amazon,' has been abandoned by tourists and residents alike. All of the hotels, restaurants and schools have padlocked their doors , closing indefinitely.

No civilians can cross the police and military lines set up about 12 kilometres from the town. Beyond that point, everything is vacant. The evacuation left four people dead and two injured, all from a same family who died in a traffic accident.