Ukraine is expected to launch a large-scale attack on the Zaporozhye Nuclear Power Plant (ZNPP) overnight, a senior Russian atomic energy industry official warned late on Tuesday. Kiev may also strike the plant with a missile stuffed with radioactive waste, he added.

The warning was voiced by Renat Karchaa, a senior aide to the head of Rosenergoatom, a subsidiary to Russia’s state-owned atomic energy giant Rosatom. The official cited intelligence data received by the industry.

“On July 5, literally overnight, while it’s still dark, Ukrainian forces will attempt an attack on the Zaporozhye plant with long-range high-precision munitions, as well as suicide drones,” he told Rossiya 24 TV channel.

Kiev is also expected to attempt a strike on the plant with a heavy, Soviet-made Tochka-U tactical ballistic missile, Karchaa went on. The munition has been filled with radioactive waste collected from the South-Ukrainian nuclear power plant, the official claimed. While Karchaa did not elaborate, the apparent goal of the secondary attack is to cause an uptick in radioactivity readings in the region should the main launch fail to damage the facility enough to cause the release of hazardous materials into the air.

The ZNPP was seized by Moscow from Ukraine early into the ongoing conflict, getting formally transferred under Rosatom management as the Zaporozhye region became incorporated into Russia after a referendum. Both Moscow and Kiev have repeatedly accused each other of subjecting the Russian-controlled facility to artillery fire and drone strikes.

The rhetoric around the plant escalated in recent weeks, with the top Ukrainian official repeatedly claiming Moscow had been preparing a nuclear incident at the ZNPP. President Vladimir Zelensky, for instance, said Moscow wanted to cause a “radiation leakage” at the plant, while his aide Mikhail Podoliak accused Russia of placing mines in the plant’s cooling pond.