3250 Ukrainians were detained by the State Border Guard Service of Ukraine in February - June 2022.
https://ua.news/ua/v-gpsu-nazvali-kolichestvo-muzhchin-kotorye-pytalis-sbezhat-ot-mobilizatsii-iz-ukrainy/

Ukrainians fled abroad from the war and mobilization for war, declared by the Kyiv authorities.

This was reported on June 10 by the Ukrainian Pacifist Movement.

At the same time, as the Movement notes, in the Soviet Union between 1955 and 1991, only about 2,000 people were detained for illegally crossing the border of the USSR.

And from 1945 to 1991, about 800 people were convicted in the USSR for illegally crossing the border.

These data were reported by the Soviet dissident Kronid Lyubarsky.
https://t.me/ukr_pacific/5918

On June 9, 2022, the prosecutor's office of the Kovel district of the Volyn region (western Ukraine) announced that there would be a trial of a local resident who refused to participate in the war:
https://vol.gp.gov.ua/ua/news.html?_m=publications&_c=view&_t=rec&id=314537.

A resident of the Kovel district will be tried under Article 336 of the Criminal Code of Ukraine ("evasion of conscription for military service during mobilization").

He faces 5 years in prison.

On May 18, 2022, a petition was registered on the website of the President of Ukraine to lift the ban on leaving Ukraine for men aged 18 to 60: https://petition.president.gov.ua/petition/139292.

According to Ukrainian law, if the petition gains more than 25,000 votes in its support, the president must answer the questions raised by the petition.

The petition to lift the ban on the exit of men from Ukraine very quickly gained more than 25,000 votes, but there is still no answer from Zelensky.

Thus, men who do not want to fight cannot leave the borders of Ukraine, and in the part of Ukraine most controlled by the Kyiv authorities, there are roundups of Ukrainians who are subject to mobilization.

Many mobilized in this way refuse to fight. For this, they are arrested and charged with "desertion" (Article 408 of the Criminal Code of Ukraine). They face 12 years in prison.
https://t.me/repressionoftheleft/500

One of the founders of the Ukrainian Pacifist Movement, journalist Ruslan Kotsaba, recorded a video in 2015 calling for an end to the war.

For this, he was accused by the Security Service of Ukraine of "state treason" and "opposing the armed forces of Ukraine."

Kotsaba spent a year and a half in a pre-trial detention cell, but was acquitted by the Ivano-Frankivsk Court of Appeal (western Ukraine).

The Supreme Court of Ukraine overturned the decision of the Court of Appeal that justifies Kotsaba and court hearings in the court of first instance in the Ivano-Frankivsk region continue.

Ruslan himself is now hiding from the Kyiv authorities.