The group of men and women entered the Sakharov Center in Moscow on September 29, carrying a large jar containing a red liquid with a label saying "Blood of Donbas Children Killed by Ukrainian Army."
They tore down all of the photos in the exhibition, which had been organized by the Center of Documentary Photography, demanding its closure and threatening to sue the organizers for "propagating extremism."
The photos were taken in Ukraine's Donetsk and Luhansk regions, where government forces have been fighting Russia-backed separatists since April 2014.
On September 28, a man sprayed the photographs with red paint and called the photographers -- Alyaksandr Vasyukovich of Belarus and Russia's Sergei Loiko -- "fascists."