Russia committed war crimes and violated international law using human shields, "little green men" and treachery during its illegal annexation of Crimea in 2014. These are the findings of the study by the President's Office in Crimea and human rights activists who authored the report, titled "Without signs, without a name, hiding behind the backs of civilians."

"Firstly, we analyzed the issue of using human shields while encircling, blocking and seizing military units of Ukraine's Armed Forces and administrative buildings. The use of human shields is new for the International Criminal Court. Such facts, of course, already existed, but "human shields" were mainly used by organized armed groups rather than states. Russia used just such a prohibited method of warfare," Permanent Representative of Ukraine's President to Crimea Anton Korynevych said at a press conference in Kyiv on Wednesday.

He pointed out that the key to this is the subjective intention to achieve a military advantage, to use civilians for this and to avoid the use of force by the Ukrainian military.

Korynevych said Russia also used "little green men," soldiers in uniform without insignia.

"Yes, there have been such cases in world history, but again it wasn't on the part of states," he said.

Korynevych said Russia's third major crime was treachery, the illegal use of emblems, uniforms of Ukraine's Naval Forces and police when blocking and seizing objects on the peninsula in 2014.

Ukrainian Helsinki Human Rights Union lawyer Maksym Tymochko said that the study is based on materials collected during visits to Criema by human rights activists, including interviews with eyewitnesses and internally displaced persons who witnessed the blocking, seizures of Ukrainian military facilities in Crimea and the use of uniforms of Ukrainian law enforcement agencies by Russian soldiers. Videos not publicly available were also used.

Crimean Prosecutor Ihor Ponochevny said the study helps law enforcement officers understand the holistic picture of what happened in the beginning of 2014 in Crimea.

"I hope that the results of this study will form the basis of the accusations that will be made to representatives of the occupying state and representatives of the occupation administration in Crimea," he said.

Regional Center for Human Rights lawyer Vitaliy Nabukhotny said the case involving the occupation of Crimea is the first since the creation of the UN, when "one state openly admits that it seized the territory of another state."

"There are many difficulties, because many norms of international law get their first application precisely in connection with Russia's annexation of Crimea," he said.

He said study is the basis of the message that was sent to the International Criminal Court in February 2019.