Ukraine has tightened its laws on military mobilization to address an acute shortage of soldiers.

Following the Russian invasion, Ukrainian men aged 18 to 60 have been banned from leaving the country.

The mobilization law that came into effect on Saturday stipulates that men in the eligible age group must now register their address and other personal information with the military within 60 days.

The measure is meant to prevent draft dodging, and comes after Ukraine lowered its mobilization age last month from 27 to 25.

An independent media outlet conducted a survey in January and February canvassing Ukrainian men between the ages of 18 and 55.

Eighteen percent of respondents said the mobilization is unnecessary, while more than 80 percent said mobilization is necessary, but must be conducted fairly.

More than 30 percent said they were ready to serve if called up, but nearly half said they were not. Amid these tensions, people are still trying illegally to leave Ukraine to escape mobilization.

Many attempts to flee to neighboring countries have been facilitated by brokers under severe conditions. Some people have lost their lives trying to cross rivers and steep mountain passes.

Radio Free Europe quoted Romanian border police as saying that around 11,000 Ukrainian men of military service age have illegally entered the country since the start of the Russian invasion.