Under martial law, Ukrainian men aged between 18 and 60, with some exceptions, are not allowed to leave the country as they may be called up for military service.As Ukraine faces the challenge of mobilizing more men for its army, a November 2023 report by the BBC indicates that around 20,000 Ukrainian men have illegally crossed the border and escaped mobilization. Many men end up crossing the border illegally with the help of smugglers, who demand vast sums only to leave the men to cross a river or mountain alone, Demchenko said.  "Every day we refuse border crossings to about 120 people," Demchenko said.Since the start of the full-scale invasion, the State Border Guard Service has uncovered about 450 criminal networks that smuggle people across the border.