Russia's Federal Security Service

Russia's Federal Security Service reported killing a suspected member of the Islamic State group preparing a terrorist assault in the city of Nizhny Novgorod on the day of the presidential election next month, news agencies said.

Russian President Vladimir Putin has said that a terrorist attack occurred in St. Petersburg on Wednesday. The head of state ordered Russia's Federal Security Service, the FSB, to act within the law when detaining criminals, but in the event of a threat to the lives of law enforcement officers, no one should be captured but should be eliminated on the spot, TASS reported.

An unidentified gunman opened fire in the receiving office of the local branch of Russia's Federal Security Service (FSB) in the Far Eastern city of Khabarovsk on Friday, the FSB Public Relations Center told TASS.

"At 17:02 local time (06:02 GMT), an unidentified man entered the FSB receiving office and opened fire before crossing the control zone," the Center said.

Russian rescuers found Dec. 26 the first parts of the Syria-bound military plane that plunged into the Black Sea, as officials said they do not suspect terrorism as the reason for the crash that killed 92 people on board.

Five explosions have taken place outside of a police station a village in southern Russia, TASS reported on Monday.

There were four attackers of the police station in the Novoselitsky district of Stavropol region, the Russian news agency quoted a local police source as saying.

Russia's Federal Security Service (FSB) has detained seven suspected members of the Islamic State group who allegedly planned terrorist attacks in Moscow, St. Petersburg and the Urals.

The group, arrested in Yekaterinburg, comprised citizens of Russia and countries of Central Asia and was led by one of its members who had  arrived from Turkey, FSB said in a statement on Monday.

Russia's Federal Security Service (FSB) on Monday said they arrested seven Islamic State members who planned to carry out terrorist attacks.

According to RT, the leader of the group that intended to stage attacks in Moscow, St. Petersburg, and the Sverdlovsk region "came from Turkey."

President Vladimir Putin probably approved a Russian intelligence operation to murder ex-KBG agent Alexander Litvinenko with radioactive polonium-210, a British inquiry into the 2006 killing in London concluded. 

Litvinenko, 43, an outspoken critic of Putin who fled Russia, died after drinking green tea laced with the rare radioactive isotope at London's Millennium Hotel. 

Zaur Dadayev has confessed involvement in the murder of Russian opposition politician Boris Nemtsov, ITAR-TASS reported on Sunday.

According to Judge Natalya Mushnikova, Dadayev's involvement was "confirmed by his confession," the newswire said.

The Islamic State (IS) group on Tuesday released online a new video purportedly showing a boy executing two alleged Russian spies in Syria.

The video, which includes subtitles in Arabic and English, shows a boy and an IS fighter standing behind the two kneeling 'spies', after which the child executioner allegedly shoots both men in the back of their heads with a handgun.