ZAPORIZHZHIA, Ukraine — Dire warnings from Russia and Ukraine about a possible attack at a nuclear power plant in southeastern Ukraine sent some nearby residents fleeing Friday and others hunkering down amid heightened international fears of a radioactive disaster.The ominous threat to the Zaporizhzhia nuclear power plant, Europe’s largest, alarmed world powers and renewed calls by U.N. Secretary General António Guterres for an immediate cessation of hostilities and access for international nuclear experts.“Any potential damage to Zaporizhzhia is suicide,” Guterres said after a meeting in Ukraine with President Volodymyr Zelensky and Turkish President Recep Tayyip Erdogan.Ukrainian officials said the Kremlin was behind explosions at the plant meant to create a “provocation.”

Russian President Vladimir Putin accused Ukraine of shelling the plant and risking a “large-scale catastrophe.” Both Russia and Ukraine are warning that the other could conduct a “false flag” attack, an operation designed to disguise the country responsible.Putin made the comments, his first about the recent fighting around the large complex along the Dnieper River, during a phone call with French President Emmanuel Macron. Like many world leaders, Macron emphasized the need for U.N. nuclear experts to visit the site under conditions laid out by Ukraine and the United Nations.In the area around the plant, some families packed up their possessions and started to flee. Fathers and husbands, unable to leave on buses with their families, helped load belongings and waved to their loved ones in tearful goodbyes at a parking lot in the city of Zaporizhzhia, 30 miles to the northeast.