CNN
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The Shiveluch volcano erupted early Tuesday morning in Russia’s far eastern Kamchatka region, spewing ash up to 20 kilometers above sea level, according to the local branch of the Russia Academy of Sciences (RAS) Geophysical Survey.

Seismic activity was first reported around 12:54 a.m. local time on Tuesday (8:54 a.m. ET on Monday), the Geophysical Survey said on Telegram, adding that the volcano was still erupting nearly 15 hours later.

Videos posted on social media from the region show a large ash cloud in the sky and ash covering roads and cars in the town of Ust-Kamchatsky, about 90 kilometers (55 miles) from the volcano.

According to satellite data, the size of the plume cloud measures 400 by 250 kilometers and has spread to the west and south of the volcano, the Geophysical Survey said.

The Institute of Volcanology and Seismology of the Far Eastern Branch of RAS said a “red” hazard designation, the highest level, has been issued for aviation and that there is a risk of hot lava flows blocking roads, Russian state news agency TASS reported.

“Molten lava flows can travel up to 20 kilometers and block the Petropavlovsk-Kamchatsky-Ust-Kamchatsky highway,” the institute said, according to TASS.

This is a developing story and will be updated.