Operations at the Zaporizhzhia nuclear plant are being suspended in case of "provocations" by Ukrainian forces, the TASS state news agency said on Monday, citing the Moscow-installed governor of the Russia-controlled part of the surrounding region.
Russia captured the plant in the early days of its invasion of Ukraine last year.
Ukraine is expected to start soon a much-anticipated counteroffensive to retake Russian-held territory, including potentially in the Zaporizhzhia region, and Russian authorities have begun evacuating people.
"We've seen the level (of water in the nearby Kakhovka Reservoir) rise to 17.08 (metres). We realise that this is manipulation. The nuclear reactors have been suspended," TASS quoted Yevgeny Balitsky as saying.
He did not elaborate.
The head of the U.N. nuclear power watchdog, Rafael Grossi, has previously said all six reactors at Europe's largest nuclear energy facility are already in "cold shutdown", meaning they are not producing electricity, but they are still loaded with nuclear material.
Grossi warned on Saturday that the situation around the plant had become "potentially dangerous" as Moscow-installed officials began evacuating people from nearby areas.
Some 3,000 people have been evacuated from villages close to the front line, TASS quoted Balitsky as saying on Monday, including around 1,000 minors.
The International Atomic Energy Agency (IAEA), which Grossi heads, has issued warnings previously about safety at the plant after shelling caused temporary power cuts.
In March the IAEA warned the plant was running on diesel generators to keep vital cooling systems going, after damage to power lines.
(Reporting by Reuters)