He reportedly called the police “infidels” during the assault in the Tatarstan region.
The attack comes a day after a woman was beheaded and two others killed in a knife attack at a church in the French city of Nice.
Russia’s Investigative Committee is treating today’s incident as an act of terrorism and opened a criminal case.
Investigators said the boy screamed “I am going to kill you all” as he stabbed the officer thrice in his hip and arm. Another police officer fired warning shots in the air before being forced to open fire. The teenager died of his wounds before medics could arrive.
Antopov was reported to be from the Altai region in Siberia and had a job working in a halal cafe named Barakat. Its owner Marat Zamaleev had served 14 years for sabotage and illegal manufacture of weapons.