A Ukrainian soldier is seen within the Azovstal Iron and Steel Works complex in Mariupol.
The last soldiers in Mariupol surrendered to Russia's forces on May 16 and have been held prisoner in territory controlled by the separatists in eastern Ukraine.
Many Russian and separatist officials have reserved a special animus for the Azovstal defenders, many of whom are members of the ultranationalist Azov Regiment, calling for them to face tribunals and even execution.
The Azov Regiment is a far-right volunteer group that has been part of Ukraine’s National Guard since 2014. Formerly a paramilitary militia known as the Azov Battalion, it espouses an ultranationalist ideology that U.S. authorities have linked with neo-Nazi extremism. But supporters see it as a patriotic and effective part of the country’s defense forces.
The proceeds from the exhibition of Kozatskiy's work will be used to buy equipment and weapons for the Azov Regiment.
On August 2, the regiment was declared a terrorist organization by Russia's Supreme Court, and family members fear this might mean those held prisoner could face trial as terrorists.
At the exhibition, Kozatskiy's mother, Iryna, said her son "wanted to convey a real picture to people. Because hearing, 'Oh, war, oh Azovstal' is one thing. And he wanted to convey what these people are, how indestructible they are. Their body is battered, the body is torn, but their soul is so luminous, shining!"
"He plays with those rays of light everywhere. These are already the last days. The pictures were taken in the last days before leaving Azovstal. They found those rays and they found a way out," she said.
After the soldiers at Azovstal were forced to surrender, Iryna says she spoke with her son several times for several minutes. The last time he called her was after the July 29 explosion at the prison in Olenivka, where dozens of Ukrainian prisoners were killed.
Moscow says the explosion was caused by Ukrainian forces using U.S.-supplied precision rockets. Kyiv accuses the Russians and separatists in Ukraine of orchestrating the explosion to cover up the torture and execution of prisoners at the site.
"On August 2, he called, said that the investigators had given him a call, and said that he was in Donetsk in a pretrial detention center," Kozatskiy's mother said. "I told him: 'Son, we are fighting for you every second with every cell. Nobody forgot about you. Don't ever think that you've been forgotten!'"
Since the publication of the photographs, Iryna says people began to recognize her on the street. She says people come up to her, say words of support, and hug her.
Azov Regiment soldier and photographer Dmytro Kozatskiy, call sign "Orest."