The health of Ukrainian director Oleg Sentsov, imprisoned in the in a high-security penitentiary known as the Polar Bear in the Yamal-Nenets Autonomous Region, has worsened.

Hromadske.ua, citing Sentsov's lawyer, reported that he has severely decreased hemoglobin, which led to anemia, and a very low pulse, about 40 beats per minute.

Sentsov's lawyer Dmitry Dinze, who twice failed to convince him to go to the hospital, said Sentsov's heart is bad and that he tolerates heat poorly.

In August 2015, the North Caucasus District Military Court in Russia's Rostov-on-Don sentenced Sentsov, who was detained in Crimea in 2014, to 20 years in a high-security penitentiary. He was accused of creating a terrorist group in Crimea.

Sentsov went on a hunger strike on May 14 and demanded that all Ukrainian citizens held in Russia be set free.