A renowned Ukrainian extreme sportsman said he scaled a landmark Moscow skyscraper and painted a star at the top of the building in the blue-and-yellow colors of the Ukrainian national flag in a burst of patriotic feeling.
The man, who goes by the nickname of "Mustang Wanted," posted a 'selfie' on Facebook that appeared to show him standing on a point of the star in the early morning light, with the streets of Moscow below him.
He also taped a Ukrainian flag to one of the points of the star.
Moscow police arrested four Russian citizens over the incident last week and charged them with hooliganism. But "Mustang Wanted" said the police had the wrong suspects.
"I am that very person, who in a burst of sincere patriotic feelings climbed on to the roof of the skyscraper on Kotelnicheskaya Embankment and colored the star decorating it in the colors of our native Ukrainian flag."
"I consider my act to be an 'art performance' and I dedicate it to Ukraine's Independence Day and also to all the lads who right now are defending my homeland. Glory to Ukraine!" he wrote on his Facebook Page.
Ukraine marks its annual Independence Day holiday on Sunday.
The sportsman said he decided to go public because the four people in Russian custody were not involved, and he feared they could become victims of a miscarriage of justice.
He said he was prepared to turn himself in to the Russian authorities, in exchange for the release of Nadezhda Savchenko, a Ukrainian army officer. She was seized by rebels, and the Ukraine government alleges she is now being held in Russia.
Mustang Wanted, also known as Grigory, is a celebrity in the niche sport of urban climbing.
He has featured in a number of viral Internet videos, and television documentaries, climbing illegally to the top of tall structures, and then hanging off them, sometimes by one hand, or performing somersaults on the top.