Russian investigators on Thursday said they had opened more than 1,100 cases into “crimes against peace” committed by the Ukrainian government, paving the way for what could turn into a mass show trial of hundreds of Ukrainian service members.

Announcing the invasion in February, President Vladimir V. Putin claimed the purpose of the offensive was to “demilitarise and de-Nazify Ukraine, as well as bring to trial those who perpetrated numerous bloody crimes against civilians”.

Russian investigators are now moving forward with cases against Ukrainian soldiers, fulfilling Putin’s promise. The servicemen include members of the Azov regiment, whose roots in far-Right movements have offered a veneer of credibility for Putin’s tenuous claims that Ukraine has been infected with Nazism.

Beyond holding trials to support its narrative of the war, the Kremlin might also turn the fate of these prisoners into a powerful bargaining chip in any future talks with Kyiv.

The Investigative Committee, the country’s top investigative body, said in a statement that hundreds of Ukrainian service members, including more than 200 officers, had already been interrogated. Among them were those captured at the Azovstal steel plant in Mariupol.

On Tuesday, Sergei K. Shoigu, the country’s defence minister, said Russia currently is holding 6,489 Ukrainian prisoners of war. Around 2,500 servicemen were captured at the Azovstal plant, President Volodymyr Zelensky said on Monday. The investigators have interviewed more than 75,000 people described as victims.

New York Times News Service