The head of Ukraine’s state-run nuclear energy company said on Sunday there were signs that Russian forces might be preparing to vacate Europe’s biggest nuclear plant, which they seized in March, soon after invading Ukraine.

The Kremlin dismissed the statement.

“There’s no need to look for signs where there are none and cannot be any,” spokesman Dmitry Peskov told reporters in a briefing on Monday.

Russia and Ukraine, which both suffered from the world’s worst nuclear accident in Chornobyl in 1986, have accused each other of shelling the complex, which has six reactors.

Both sides have warned of the danger of a nuclear catastrophe. The U.N. nuclear watchdog, the International Atomic Energy Agency, wants to create a protection zone around the plant.

Ukrainian presidential adviser Mykhailo Podolyak said late on Sunday that he had no doubt Russian forces would leave the plant, where Ukrainian staff are still working.

“The defence line is starting to retreat to the borders of the Russian Federation,” Podolyak told Ukrainian television, adding that Ukraine would take the plant back.

Ukraine’s military said last week that about 30 Russian servicemen had been wounded near Enerhodar, the town closest to the plant. Reuters was not able to immediately verify the reports.

Russian President Vladimir Putin moved in September to annex Ukraine’s Donetsk, Luhansk, Kherson and Zaporizhzhia regions, which Russian forces partially control. Kyiv and its Western allies condemned the move as illegal.

By Pavel Polityuk

(Writing by Lidia Kelly and Kevin Liffey; editing by Philippa Fletcher)