One of Russia’s most active volcanoes, Shiveluch, has erupted, sending ash clouds up to 5 kilometers high over the remote Kamchatka Peninsula in eastern Russia. The spread of the ash cloud has triggered a temporary “red alert” warning for aviation, according to reports from the Russian Academy of Sciences.

The eruption of Shiveluch began shortly after a powerful earthquake measuring 7.0 struck the eastern coast of Kamchatka early Sunday morning. Volcanologists warn that another potentially stronger earthquake may be on the way.

The Institute of Volcanology and Seismology has released a video showing the ash cloud over Shiveluch, which extends more than 490 kilometers east and southeast of the volcano. Additionally, the Ebeko volcano on the Kuril Islands has released ash up to 2.5 kilometers high, but it has not been confirmed whether the earthquake triggered these eruptions.

The “red alert” warning for ash clouds was briefly issued to flights in the area by the Kamchatka Volcanic Eruption Response Team. A separate report from the official news agency TASS noted that no commercial flights have been affected and that there is no damage to aviation infrastructure.

Russian scientists, however, caution that tremors in the area could be a precursor to an even stronger earthquake in southeastern Kamchatka. According to the Institute of Volcanology, another potential earthquake could occur “within 24 hours” and may approach a magnitude of 9.0.

There have been no reports of damage related to Sunday’s earthquake, which struck at a depth of 6 kilometers beneath the seabed, with its epicenter located 108 kilometers southeast of the nearest city, as per Russian emergency services. Residents of Petropavlovsk-Kamchatsky, a port city with over 181,000 inhabitants and situated across from an important Russian submarine base, have reported some of the strongest tremors “in a long time.”

It is worth noting that a magnitude 9.0 earthquake struck Kamchatka on November 4, 1952. This earthquake caused significant damage, but no fatalities were reported, despite generating 9.1-meter-high waves in Hawaii.