Gunman 'with hatred for ethnic minorities' killed two in security service office, one in an earlier shooting, before he was 'eliminated'.
The armed man was named by some sources as Anton Konev. Picture: The Siberian Times
The armed man named by some sources as Anton Konev killed an instructor at a local rifle club before the shooting at the foyer of the FSB regional branch in the Russian Far East city.
One FSB staffer died along with a visitor from an ex-Soviet republic.
Islamic terrorist grouping IS claimed responsibility for the incident but this is strongly doubted by Russian counterintelligence.
The gunman was 'a native of Khabarovsk territory born in 1999 and there is the evidence of his affiliation with a neo-Nazi grouping', said an FSB spokesman.
The attacker did not have explosives on him.
He stole a Saiga carbine and two handguns as he killed the rifle club instructor.
A multiple murder investigation has been opened. Pictures: Typical Khabarovsk
A multiple murder investigation has been opened and Investigative Committee (IC) chairman Alexander Bastrykin dispatched a team of 'highly expert investigators and detectives' to Khabarovsk to probe the crime.
IC spokeswoman Svetlana Petrenko said: "Investigators do not have any evidence that would confirm the attacker's links to an international terrorist organisation, which ostensibly claimed responsibility for the crime.'
Evidence so far points to 'the crime having been committed by an advocate of neo-Nazi outlooks, who espoused hatred towards people of other ethnic identities'.
He is believed to have been a member of a far-right movement called Shtolts, reported RBC citing FSB sources.
'They consider themselves 'fighters for morality'. They also oppose illegal migration,' said the source.
The group has around 15 members aged 17 to 20.
The man opened fire at the FSB office without clearing security, before he was shot. Pictures: The Siberian Times, Typical Khabarovsk
He opened fire at the FSB office without clearing security, before he was shot dead.
'The attacker was neutralized,' said the FSB.
One person was wounded in the incident, also from an ex-Soviet state.
The so-called Islamic State 'news outlet' Amaq issued a brief claim in Arabic saying "IS fighter attacked a Russian Federal Intelligence office in Khabarovsk killing three of them [personnel] and wounding others."
Security is high across Russia after 15 passengers died in a suicide bombing of the St Petersburg metro.
The suspected suicide bomber and his alleged accomplices were from Central Asia.
Farewell message in Russian sent by Anton Konev. Pictures: The Siberian Times, Typical Khabarovsk