KYIV, Ukraine (AP) — The United Nations atomic watchdog warned of a potential threat to nuclear safety due to a spike in fighting near Europe’s largest nuclear power plant in Ukraine, whose forces continued pressing their counteroffensive on Saturday.

The International Atomic Energy Agency said its experts deployed at the Russia-occupied Zaporizhzhia Nuclear Power Plant reported hearing numerous explosions over the past week, in a possible indication of increased military activity in the region. There was no damage to the plant.

“I remain deeply concerned about the possible dangers facing the plant at this time of heightened military tension in the region,” IAEA Director General Rafael Mariano Grossi warned in a statement issued late Friday.

He noted that the IAEA team was informed that staff at the nuclear power plant had been reduced temporarily to minimum levels due to concerns of more military activity in the area.

“Whatever happens in a conflict zone, wherever it may be, everybody would stand to lose from a nuclear accident, and I urge that all necessary precautions must be taken to avoid it happening,” Grossi said.

The IAEA has repeatedly expressed concern that the fighting could cause a potential radiation leak from the facility, which is one of the world’s 10 biggest nuclear power stations. The plant’s six reactors have been shut down for months, but it still needs power and qualified staff to operate crucial cooling systems and other safety features.

As Ukrainian forces pressed to expand their gains after recently capturing the village of Robotyne in the Zaporizhzhia region, the U.K. Defense Ministry noted in its latest report that Russia has brought in reinforcements to stymie the Ukrainian advances.

“It is highly likely that Russia has redeployed forces from other areas of the frontline to replace degraded units around Robotyne,” it said. “These redeployments are likely limiting Russia’s ability to carry out offensive operations of its own along other areas of the front line.”

The Washington-based Institute for the Study of War noted that the Russian military has made notable changes to its command and control structure to “protect command infrastructure and improve information sharing.”

Russian forces have continued their barrage across Ukraine. The regional authorities in the northeastern region of Sumy that borders Russia said that the latest Russian shelling left four people wounded, one of whom later died in a hospital.

The Kremlin reaffirmed Saturday that Russia will not extend a landmark deal allowing Ukraine to export grain safely through the Black Sea until the West fully meets Moscow’s demands regarding its own agricultural exports.

Kremlin spokesman Dmitry Peskov commented on reports that Western powers were allegedly discussing a deal that would allow the Russian Agricultural Bank to open a subsidiary that would be reconnected to the SWIFT payment system and meet other Russian demands. He said that Moscow expects the West to fulfill the original agreements to facilitate Russian agricultural exports that were reached in July 2022.

“For instance, they are now saying that the West is allegedly ready to promise to open SWIFT for a subsidiary of the Russian Agricultural Bank, but the thing is that the agreements envisage SWIFT access for the Russian Agricultural Bank, not its subsidiary,” Peskov said in a conference call with reporters.

He added that “because they have already made a lot of promises, we considered ourselves entitled and obligated to wait first for the implementation before resuming the deal.”

Russia refused to extend the deal in July, complaining that a parallel agreement promising to remove obstacles to Russian exports of food and fertilizer hadn’t been honored. It said restrictions on shipping and insurance hampered its agricultural trade, though it has shipped record amounts of wheat since last year.

Ukraine and its Western allies have dismissed the Kremlin’s demands as a ploy to advance its own interests.

On Saturday, Japanese Foreign Minister Yoshimasa Hayashi arrived to Ukraine for an official visit and prayed at a church in the Kyiv suburb of Bucha, where some of the worst atrocities of Russia’s war occurred early during the invasion.

“I am grateful to Japan for remaining our key partner in Asia and supporting Ukraine,” Ukrainian President Volodymyr Zelenskyy said.