About 150 people had returned to the area around Chaitén despite it being virtually destroyed last May by the first eruption in 9,000 years of a nearby volcano of the same name.

Chile’s emergency service agency said any new explosion of the smoldering mountain could send a huge cloud of super-heated debris and gas cascading into the heart of Chaitén.

“The government's not going to allow people to burn themselves up or commit collective suicide,” Justice Ministry spokesman Francisco Vidal told reporters.

A navy boat soon afterwards removed all 17 youths in the group over the objections of some parents.

The volcano’s newest eruptions came only days after the government announced it would not rebuild Chaitén, which formerly had a population of about 4,000, in the same location.

Most of its inhabitants were relocated to the nearby towns of Castro, Osorno and Puerto Montt before their homes were wrecked by falling ash and a flood of water and debris that submerged the city after the eruption.

Photo: Sergio González - El Mercurio