“IAEA experts believe there is no immediate threat to nuclear security,” but “that could change at any time,” Grossi said. “Any military action that endangers nuclear security, nuclear safety, must be stopped immediately,” he added. “These military actions near such a large nuclear facility could lead to very serious consequences.” The Zaporizhzhia facility — the largest nuclear plant in Europe — occupies a sprawling site on the Dnipro River near the Russian-held town of Enerhodar. It has continued to operate at reduced capacity since Russian forces seized it in early March, with Ukrainian technicians remaining on the job. Russia and Ukraine have so far been unwilling to agree to an IAEA inspection of the station and have accused each other of bombing the facility — actions the IAEA said violated “essential pillars of nuclear safety and security.” Russia’s UN ambassador Vassily Nebenzia on Thursday blamed Ukraine for the bombings and urged supporters of Kiev to stop the attacks and prevent a catastrophic radiation leak. But Ukrainian President Volodymyr Zelensky pointed the finger at Moscow, which he said was putting all of Europe at risk. “Only the complete withdrawal of the Russians from the territory of the Zaporizhzhia nuclear power plant and the restoration of Ukraine’s full control over the situation around the plant will guarantee the restoration of nuclear safety for all of Europe,” Zelensky said. Ukraine’s nuclear agency Energoatom said 10 shells landed near the complex on Thursday, preventing a shift handover. “For the safety of nuclear workers, the buses with the next shift’s personnel returned back to Enerhodar,” the agency said. “Until the situation is finally settled, the workers of the previous shift will continue to work.” Energoatom said radioactivity levels at the site remained normal, despite the new attacks. Several Western and Ukrainian officials believe Russia is using the giant nuclear facility as a bastion to shield its troops and launch attacks because they assume Kyiv will not fire back and risk a crisis. US Secretary of State Antony Blinken accused Moscow of using the plant to shield its forces, while Britain’s Ministry of Defense said in a recent security assessment that Russia’s actions at the complex were sabotaging the security of its operations. The Ukrainian mayor of Enerhodar, Dmytro Orlov, said in late July that Russian forces had been observed using heavy weaponry near the plant because “they know very well that the Ukrainian Armed Forces will not respond to these attacks, as they can damage the nuclear energy. plant.” The US on Thursday backed Ukraine’s calls for a demilitarized zone around the facility, while at the UN, Bonnie Jenkins, US undersecretary for arms control and international affairs, said Russia was responsible for the “nuclear dangers” at the factory. He warned the UN Security Council that “the many consequences of this conflict, including the situation at the Zaporizhzhia nuclear power plant, will only end when Russia ends its war.” UN Secretary-General Antonio Guterres — who previously called the factory bombing “suicidal” — said Thursday in a statement that he was “gravely concerned.” “We must be clear that any potential damage to Zaporizhia or any other nuclear facilities in Ukraine, or anywhere else, could lead to catastrophic consequences not only for the immediate vicinity, but for the region and beyond,” he said. CNN’s Sugham Pokharel, Jennifer Hansler, Tim Lister, Yulia Kesaieva and Tara John contributed to this report.