(Reuters) - Chile's National Geology and Mining Service, Sernageomin, on Sunday raised the alert level for the Villarrica volcano from yellow to amber, citing a gradual increase in volcanic activity.

One of South America's most active volcanoes, Villarrica has a 200 meter-wide open crater and last erupted in 2015, sparking a mass evacuation but ultimately no injuries.

An amber alert means there is a greater probability that an eruption will take place in the coming days or weeks.

(Reporting by Oliver Griffin in Bogota; Editing by Matthew Lewis)