The 51-year-old suspect entered the hospital in the city of Bratsk with a hunting rifle and took five patients and one doctor hostage, RIA Novosti reported.
Police said the suspect demanded a lethal injection of unspecified narcotics.
He was detained and the hostages were freed without injury, police said.
Police are investigating the incident and said the suspect may face charges of hostage-taking, illegal production of a weapon and robbery.
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