Berlin, Aug 22 : The leaders of Germany, France, Britain and the US have called for warring sides to show restraint around Ukraine's embattled Zaporizhzhya nuclear power plant and for UN inspectors to immediately have access to the sprawling site. The Zaporizhzhya plant, located in the southern Ukrainian city of Enerhodar, was seized by Russia in early March. Fighting intensified at the complex in recent weeks, prompting ominous warnings by world powers of a potentially catastrophic escalation. US President Joe Biden, French President Emmanuel Macron, German Chancellor Olaf Scholz and British Prime Minister Boris Johnson spoke about Zaporizhzhya and the wider Ukrainian war in telephone call on Sunday. They agreed on "the need to avoid military operations near the plant" and for nuclear experts with the International Atomic Energy Agency (IAEA) to inspect the facility in order help ensure its safety and security, a White House statement said. In Germany, Scholz's spokesman said they were in agreement "that support for Ukraine in its defence against Russian aggression would be continued on a sustained basis." Europe's largest nuclear power plant, with six reactors, is strategically important for Ukraine's electricity supply. Kiev says Russian troops use the plant as a shield from which to fire on locations on the opposite bank of the Dnipro reservoir, because it knows Ukrainian forces will be hesitant to fire toward the sensitive site. The Kremlin and its local representative claim that Ukrainian "terrorists" are the ones firing the shots. Russia says that Ukraine is bombarding the plant with the help of drones, heavy artillery and rocket launchers. In most cases, Russian air defence intercepts the projectiles, it says. Nevertheless, some infrastructure has previously been hit, although so far critical safety and control systems have not been damaged. No increased radioactivity has been registered so far. Russia has rejected international calls to withdraw its troops from the site, but has said it would allow IAEA experts to assess the plant. Yet a number of disagreements between Moscow and Kiev on the details, including what a travel route for IAEA inspectors might look like, has slowed down the mission. Former world heavyweight boxing champion Wladimir Klitschko, the younger brother of Kiev mayor and fellow former superstar boxer Vitali Klitschko, said it was unclear how Ukrainian operating staff still working inside the plant were holding up. "The world needs to understand if (Zaporizhzhya) is going off, there's going to be Fukushima and Chernobyl in multiple times," he told Britain's Times Radio on Sunday. He said the plant and the nuclear specialists working there were being held "hostage" by Moscow. Elsewhere, the Ukrainian General Staff said late Sunday it had repelled Russian advances in the eastern Donetsk region toward the cities of Slovyansk, Kramatorsk and Avdiivka. A lawmaker from the mostly Russian-occupied southern region of Kherson reported that Ukrainian forces succeeded in destroying a Russian ammunition depot during a counteroffensive at the weekend. On Sunday, day 179 of the war, the Russian side stated that its own air defences had repelled several Ukrainian attacks over the weekend. This included over the Black Sea peninsula of Crimea, which was annexed by Russia in 2014, according to the Russian authorities. Air defences had intercepted "objects" that were on approach to Russia's Belbek military airfield near Sevastopol, the major port city's head of administration, Mikhail Razvoshev, wrote on Telegram late Sunday. Earlier on Saturday, there had been an explosion in Sevastopol. Russian reports said that a drone had targeted the headquarters of the Black Sea Fleet, but that there were no casualties. In Crimea, which belongs to Ukraine under international law, there have recently been repeated blasts, including on an ammunition depot. Kiev welcomes the attacks, but has not directly accepted responsibility for them. /IANS