A drone strike on Monday killed an employee of the Russian-occupied Zaporizhzhia nuclear power plant in Ukraine, the UN's nuclear watchdog said. Captured by Russian forces in March 2022 shortly after Moscow launched its full-scale invasion of Ukraine, Zaporizhzhia is Europe's largest nuclear facility and has repeatedly been at the center of safety concerns during the war. "The IAEA has been informed that one employee (of the plant) was killed in a drone attack today, in the latest incident affecting plant personnel and further endangering nuclear safety and security during the military conflict," the International Atomic Energy Agency said in a post on X. An employee of the nearby Zaporizhzhia Thermal Power Plant, a conventional fossil-fuel power station, was also killed by a drone on Monday, the IAEA said. The Vienna-based agency last reported that an employee was killed in a drone attack at the nuclear plant in late October, reportedly a welder at a repair workshop. IAEA director general Rafael Grossi "strongly condemns the deadly strikes and says they represent unacceptable attacks violating indispensable nuclear safety pillars", the organization said. "All such attacks on nuclear plant workers must stop immediately" and "all nuclear plant personnel must be able to carry out their important work without undue stress or fear", the IAEA said. Russia and Ukraine regularly accuse the other of attacking the site, which sits on the banks of the Dnipro River near the war front line. IAEA teams have had a permanent presence at the plant since September 2022. Zaporizhzhia's six reactors have been shut down since 2022.