Dozens of Russian military aircraft have been destroyed in an unprecedented drone attack deep inside Russia, a Ukrainian official has said, the day before critical peace talks between Moscow and Kyiv resume in Istanbul.

The drone attacks came on the eve of expected peace talks in Istanbul between Russia and Ukraine, which were already strained by uncertainty and pressure from U.S. President Donald Trump.

Check out the top points detailed by Ukrainian President Volodymyr Zelenskyy of the drone attack carried out by Russia.

The attack followed a night of bombardment, with Russia launching 472 drones, Ukraine’s air force said. Earlier Sunday, Ukraine’s army said a Russian missile strike on an army training unit killed at least 12 Ukrainian service members and injured 60.

In an undisclosed location near the front line, Vanya, a Ukrainian soldier, traverses through a field covered in the traces of a deadly Russian weapon.