A 'supervolcano' in a densely populated part of Italy could be on the verge of its first eruption since 1538, researchers have warned.
The Campi Flegrei volcano near Naples, southern Italy, has become weaker and more prone to rupturing, making an eruption more likely, the experts say.
Located about nine miles (14.5 km) to the west of Naples, it is one of the few active supervolcanoes in the world.