New Delhi, April 27 -- Strikes across Ukraine, Russian-occupied territory and Russia over the past day killed at least 16 people, authorities said Sunday as the 40th anniversary of the Chernobyl nuclear disaster prompted new warnings about risks posed by attacks near the plant during Russia's more than four-year invasion of its neighbor.

Ukraine's President Volodymyr Zelenskyy marked the anniversary with a warning that Russian attacks risk repeating history.

"Russia is once again bringing the world to the brink of a man-made disaster - Russian-Iranian Shaheds regularly fly over the plant, and one of them struck the confinement last year," he wrote on Facebook, referring to the Iran-designed drones that have wreaked havoc since Moscow la...