A total of 180 out of 438 Ukrainian servicemen have gone from Russia's Rostov region to Ukraine, press office head of the Russian Federal Security Service (FSB) border division for the Rostov region Vasily Malayev told Interfax on Monday.

"Right now at 1429 Moscow time 180 Ukrainian troops, who crossed the Russian border in the Rostov region at night, went to Ukraine by buses," Malayev said.

According to Malayev, the servicemen willing to go to Ukraine went and the others are remaining in the Rostov region for now.