Human rights activists have submitted to the prosecutor of the International Criminal Court (ICC) in The Hague a motion regarding Russia's crimes against over 100 illegally detained citizens of Ukraine, most of whom are Crimean Tatars, in the occupied Crimea.

Speaking at a press conference in Kyiv on Thursday, Head of the Center for Public Freedoms Oleksandra Matviychuk said the number of prisoners and persecuted persons in Russian-occupied Crimea had been on the rise, an UNIAN correspondent reports.

"Now there are about 100 people on our list of political prisoners, and most of them are Crimean Tatars," she said, adding that the Ukrainian state has no leverage to protect its citizens living under the Russian occupation in Crimea.

In turn, Scott Martin, a U.S. lawyer with Global Rights Compliance LLP said the prosecutor of the International Criminal Court in The Hague received reports on about 104 Ukrainian citizens, most of whom had been detained or arrested in the occupied Crimea on terrorism charges.

Gregory Frolov, a representative of Free Russia Foundation NGO, added that materials for submission to the ICC had been gathered over the past six to eight months. According to him, the motion was submitted last week.

The organization he represents is deeply engaged in efforts toward the release of Ukrainian political prisoners, added Frolov.

Read alsoZelensky elaborates on Crimea-related issues to be raised internationally"And so that the people who actually built this repressive machine, being directly responsible for the ruined lives and for the years they've spent in inhumane conditions, be punished," Frolov said.

In turn, Matviychuk expressed hope that in the near future the ICC would decide on transition from the stage of preliminary study of the Ukraine case (which, among other things, includes issues of crimes against humanity and war crimes committed in Crimea and Donbas) to the stage of independent investigation.

"Every year the Office of the Prosecutor reports on the progress of preliminary investigations. When we analyze what they write on the Ukrainian case, in particular the issue of occupied Crimea, we find the references to political persecution, but not as many as we'd like to see. It's the gap we'd like to fill with our motion," Matviychuk explained.

She said since the onset of the Russian occupation in 2014, Crimea, as a former resort destination, has been turning into a massive military base, with the ever-growing military contingent and weapons arsenals.

"Even now, we can say Russia is conducting military operations in Syria using a military base located in Crimea. In particular, missiles are delivered from there, then to be used in Syria hostilities," Matviychuk said.

Read alsoKuleba urges international community not to turn a blind eye to Russia's terrorist methodsRussia's actions in occupied Crimea: Human rights activists elaborate

According to her, Russia is pursuing a policy of population resettlement to Crimea to build such a base.

"The occupying authorities of Crimea and the Russian Federation view the entire population of the peninsula as potentially disloyal," she said.

Matviychuk added that resettlement was carried out in two ways.

"The first is the path of controlled migration with the implementation of various programs for the resettlement of Russian citizens from different regions of Russia to the occupied Crimea," the rights activist said.

Another one is the deployment of a system of political persecution, which sends the proactive minority a signal to flee the peninsula, she said.

According to Matviychuk, political persecution manifests itself in various ways, through a variety of enforcement mechanisms (searches, interrogations, fabricated criminal and administrative cases), as well as illegal methods, such as assaults, abductions, torture, and murder.