An overnight Ukrainian drone attack in southern Russia’s Saratov region damaged several high-rise apartment buildings and injured multiple people, local authorities said early Monday. “Air defense systems shot down drones early this morning,” Saratov region Governor Roman Busargin wrote on Telegram. “Debris fell on residential buildings in both Saratov and Engels.” The cities of Saratov and Engels lie along the Volga River, about 730 kilometers (454 miles) southeast of Moscow. Flights at the regional airport — located north of the capital city — were briefly restricted in the morning. Russia’s…