A band of cloud had wrapped itself around the peak as lava spewed into the air, giving the entire landscape an eerie blood-red glow.  

Villarrica, located near the popular tourist resort of Pucon around 750 km (460 miles) south of the capital Santiago, is among the most active in South America.

On March 3 a short-lived eruption of ash and rock led to the evacuation of thousands from the nearby area. 

Britain's Met Office told MailOnline that the clouds wrapped around the volcano are lenticular clouds, which are formed, it said, when the air is stable and winds blow from the same or similar direction at many levels of the troposphere. 

It said: 'As the wind blows across hilly or mountainous regions, the air undulates in a downstream train of waves. If there is enough moisture in the air, these waves will condense to form the unique appearance of lenticular clouds. The clouds can be seen as far as 60 miles downwind of the hills or mountains that led to their formation and they are believed to be one of the most common explanations for UFO sightings across the world.'

In late April Chile's Calbuco volcano erupted, releasing a large column of smoke in a towering arc, just over a week after it spectacularly roared to life following half a century of inactivity.

'As predicted, the third eruptive pulse at the Calbuco volcano has arrived. Red alert,' the National Geology and Mines Service wrote on its official Twitter account at the time. 

A large plume of dark gray smoke and ash rose from the crater, prompting authorities to evacuate a 20-kilometer (12-mile) radius around the volcano, where workers and residents had been granted limited access to begin the clean-up effort.

'All of a sudden they ordered us to evacuate again so we left in our cars. But it was calmer than last time,' said Horacio Camano, a resident of La Ensenada, a town of 1,500 people at the foot of the volcano.

TV images showed thousands of people rushing to schools to pick up their children or lining up at gas stations to fill up their cars in the cities closest to the volcano, Puerto Montt and Puerto Varas.

(dailymail.co.uk)