SANTIAGO, Chile

 Authorities in southern Chile continued to monitor the Calbuco volcano Thursday after it erupted twice in the last 24 hours, warning that a possible third eruption could be stronger thant the previous ones.

Approximately 4,000 residents have been evacuated from a 12-mile (20 kilometer) radius of the volcano, located about 600 miles (1,000 kilometers) south of the capital Santiago.

Ash and small pebbles have rained as far away as Bariloche in neighboring Argentina, coating roads, buildings and farmlands since the volcano began erupting Wednesday.

Chilean President Michelle Bachelet and a number of ministers have traveled to the nearby city of Puerto Montt to coordinate the government’s response while troops and extra police have been brought in to ensure residents evacuate.

Locals have been warned to use masks to avoid inhaling dust or toxic gases from the volcano.

No casualties have been reported as a result of the eruption and one young hiker reported missing during an eruption has since been found.

Flights have been cancelled and schools closed through much of southern Chile as the ash cloud spreads north.

The eruption comes at a difficult time for Chile’s government that is still dealing with the aftermath of flashfloods that whipped northern Chile four weeks, killing 30 and leaving 80 missing. The cost of that cleanup has been put at $1.5 billion.

“We will have to use the resources which are available and we will see later if we need more,” the president said before leaving for the disaster zone.

The 2,000-mile (3,200-kilometer) high Calbuco is considered the third most active of the almost 4,000 volcanoes that exist in Chile. It last erupted briefly in 1972 although a series of eruptions in the late 19th century lasted almost two years.

The national mining and geology service, Sernageomin, is now monitoring the volcano carefully for signs of further activity.

“Hundreds of tremors were counted during the two eruptions … the second was stronger,” national director Rodrigo Alvarez said Thursday.

Although volcanic activity has subsided during the day, special attention is being paid to the volcano’s dome for fear it could collapse in any further eruption.