More than 3000 villagers evacuated as volcano erupts in Chile

A volcano in southern Chile has begun erupting, forcing the evacuation of some 3000 people in nearby villages.

The 2800m Villarrica volcano, one of Chile's most active, began erupting around 3am local time, prompting authorities to declare a red alert and cancel classes in schools, the National Emergency Office said.

As sirens sounded, Chilean TV footage showed lava spilling from the volcano about 800 kilometres south of the capital Santiago.

Tall plumes of ash spewed three kilometres above sea level, but hours later there were no longer any visible signs of eruption.

Still, President Michelle Bachelet appealed for calm and authorities blocked roads leading to the area around the volcano.

"I am calling for calm. We are monitoring and evaluating the situation closely," Bachelet said following a meeting with the country's emergency committee.

Villarrica is considered one of the most active volcanoes in all of South America, and draws crowds of tourists each year, with hikers climbing its slopes in the summer months to see inside its crater.

Its last major eruptions were in 1984 and 2000.