A Ukrainian drone attack started a fire at an oil refinery in southern Russia, forcing it to halt operations, regional authorities said early Thursday, adding that there were no casualties. Russia’s Defense Ministry said 13 drones were destroyed overnight in annexed Crimea, six in the southwestern Belgorod region and an anti-ship missile was shot down in the southern Rostov region. In the city of Rostov-on-Don, dozens of emergency personnel rushed to put out the flames at the Novoshakhtinsk refinery, according to Rostov region Governor Vasily Golubev. “Following a drone strike, a fire broke ou…