Igor Kirillov
Igor Kirillov, a lieutenant general, in Russia. AFPTV/AFP via Getty Images

An Uzbekistan man has been detained by authorities, suspected in the shocking bombing of Igor Kirillov, a senior general, and his assistant in Moscow.

The Russian Federal Security Services (FBS) has detained a 29-year-old, unidentified man for the killing of Lieutenant General Igor Kirillov, the country's chief of chemical weapons and his assistant in Moscow, the BBC reported.

The detained man allegedly placed an explosive device on an electric scooter near Kirillov's home, and remotely detonated it when the lieutenant emerged on the Moscow streets.

Russia claims the man was recruited by Ukraine intelligence agents and paid $100,000 and promised to be relocated to Europe to complete the killing, the news outlet reported.

A Ukrainian source told the BBC in an interview that Kirillov was a "legitimate target" who committed war crimes like chemical attacks during Russia's invasion, led by President Vladimir Putin, of Ukraine.

The United Kingdom has also alleged that Kirillov used chemical weapons against Ukrainians.

Kirillov was charged on Monday, with Ukraine authorities saying he was "responsible for the mass use of banned chemical weapons."

Separately, the European Union sanctioned Russia's military intelligence for "hybrid attacks," a first-of-its-kind sanction, that includes disinformation, cyber strikes, and arson, in an attempt to destabilize Europe.