A magnitude 7.2 earthquake struck off Russia's eastern coast in the Kamchatka region early on Sunday at a depth of 51 km (32 miles), according to the European Mediterranean Seismological Centre (EMSC), soon after which the Shiveluch volcano erupted.
The volcano began belching lava and ash after the earthquake, Russian news agency TASS reported, citing the Institute of Volcanology and Seismology of the Far Eastern Branch of the Russian Academy of Sciences .
Scientists said an 8km ash column was rising as high as 8 kilometers above the sea level.
The volcano had also released a gush of lava, they added.
No casualties have been reported so far.
There was no clarity, however, on tsunami warnings, with Kamachatka branch of Russia’s ermgency ministry ruling out a threat even as the US National Tsunami Warning Centre indicating possibilities of a sea surge.
Aftershocks of 3.9 to 3.0 have also been recorded, Russian officials said.
The earthquake struck 29 kilometres below surface, the US Geological Survey said.
Its epicentre was approximately 102 kilometres east of a volcano-ringed Petropavlovsk-Kamchatsky, a port city.
A key Russian submarine base is located across the bay.
The Russian emergencies ministry’s department in the Kamchatka region was also reporting that the daily life of the local residents was not affected.
A press statement from the ministry’s department said a minor ashfall had been reported in the morning of August 18 (local time).
If the eruptions continued the ash columns were likely to rise to the altitude of up to 10 km above the sea level, the press statement warned.
TASS also reported that The Telegram channel of the Institute of Volcanology and Seismology of the Far Eastern Branch of the Russian Academy of Sciences, had mentioned a code red being issued for local and international flights in the area.
"The ash cloud stretches 492 km to the east and southeast of the volcano. Aviation code red. The volcanic activity is potentially hazardous to local and international flights," TASS cited scientists as saying in a statement.
Shiveluch, at 3,283 metres, is one of the largest volcanoes on Kamchatka. Comprising three elements, the ‘Old Shiveluch’ stratovolcano, an ancient caldera, and the active ‘Young Shiveluch.’
The lava dome of ‘Young Shiveluch’ is 2,500 meters high.
The volcano is located at the intersection of the Kuril-Kamchatka and Aleutian island arcs at a distance of 50 km from the village of Klyuchi in the Ust-Kamchatsky District and 450 km from the regional capital, Petropavlovsk-Kamchatsky, TASS reported.