One of Russia's most active volcanoes erupted on Sunday, spewing plumes of ash 5 kilometers into the sky over the far eastern Kamchatka Peninsula and briefly triggering a "code red" warning for aircraft.

The Shiveluch volcano began sputtering shortly after a powerful magnitude-7.0 earthquake struck off Kamchatka's east coast early Sunday.

Volcanologists from the Russian Academy of Sciences warned that another, even more potent earthquake may be on the way.

The tremors in the area may be a prelude to an even stronger earthquake in southeastern Kamchatka, Russian scientists warned. The academy's Institute of Volcanology and Seismology said a potential second quake could come "within 24 hours" with a magnitude approaching 9.0.

The institute released a video showing the ash cloud over Shiveluch. It stretched over 490 kilometers to the east and southeast of the volcano.

The Ebeko volcano on the Kuril Islands also spewed ash to a height of 2.5 kilometers, the institute said. It did not explicitly say whether the earthquake touched off the eruptions.

A "code red" ash cloud warning briefly put all aircraft in the area on alert, the Kamchatka Volcanic Eruption Response Team reported. A separate report on Sunday published by the official Tass news agency said that no commercial flights had been disrupted and no damage to aviation infrastructure.

There were no immediate reports of injuries from Sunday's earthquake, according to Russian emergency officials.