All workers at Japan’s Fukushima Daiichi nuclear power plant were evacuated on Wednesday as a precautionary measure following a powerful earthquake off Russia’s eastern coast, the plant’s operator, TEPCO, announced.

A TEPCO spokesperson confirmed that “all workers and staff have been evacuated” and noted that “no irregularities” were observed at the plant, which has been undergoing decommissioning since the catastrophic 2011 earthquake and tsunami.

The evacuation was triggered by concerns over a possible tsunami resulting from the offshore quake, which registered a magnitude of 8.7, making it the strongest in the region since 1952, according to Russian geophysical authorities.