A Ukrainian soldier looks through the scope of his gun in a shelter located in the front line with Russia-backed separatists in the small city of Shyrokyne, 25 km from Azov Sea port of Mariupol, on November 28, 2018. - Ukraine's president imposes martial law in border regions on November 28, 2018 for 30 days in 10 regions bordering Russia, the Black Sea and the Azov Sea. (Photo by Sega VOLSKII / AFP)