Ukrainian drone attacks overnight Thursday killed three people in Russia's Rostov region, the regional governor said, as the conflict rages on despite US efforts to stop the fighting.An attack caused a fire on a cargo ship in the port of the regional capital, killing two crew members and injuring three, acting regional governor Yuri Sliusar said on Telegram. The blaze was later extinguished.A civilian was also killed and six others injured in the town of Bataysk, near the port facilities, he said.