A volcano in eastern Russia previously considered extinct may have woken up, with potentially catastrophic consequences, scientists have said.

The Bolshaya Udina volcano, which is part of a complex of volcanoes on Russia's Kamchatka Peninsula, is around 10,000ft high and until 2017 was dismissed as inactive.

But an international team of scientists have now suggested otherwise, after they conducted a two-month study of the volcano last year.

In that time, they recorded an "elliptical cluster" of 559 seismic events there - compared to around 100 weak events between 1999 and 2017.

“Since late 2017, continuing seismic activity beneath Bolshaya Udina has been recorded, which may indicate the possible awakening of this volcano complex,” wrote the researchers, who published their findings in the Journal of Volcanology and Geothermal Research.

They added: “[The findings] may indicate the presence of magma intrusions with a high content of melts and fluids, which may justify changing the current status of this volcano from ‘extinct’ to ‘active'."

Ivan Kulakov, a geophysicist from Russia's A.A. Trofimuk Institute of Petroleum Geology and Geophysics and lead author of the paper, told Science in Siberia that when a volcano is silent for a long time, its first explosion can be “catastrophic”.

“A large amount of ash is thrown into the air, it is carried far away, and not only to the surrounding settlements,” he said, “but also large territories all over the planet can suffer. Recall Pompeii: the awakening of Vesuvius was preceded by a lull for several thousand years.”

Mr Kulakov told CNN there is around a 50 per cent chance Bolshaya Udina will erupt.