There's some pretty ominous news for people in the Italian city of Naples.
The dormant volcano under the city is building up pressure and it could be on the verge of erupting.
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This is the conclusion of Italian and French scientists who have published their findings in a scientific journal.
The volcano is known as Campi Flegrei and it lies directly underneath the Bay of Naples.
It's been dormant for a long time but now it's reawakening and there is magma rising within it.
It's currently unclear when or if it will erupt but it does pose a threat to the half a million people who live nearby.