Russia’s top security agency says that it has arrested several suspects accused of involvement in an alleged Ukrainian plot to assassinate senior military officers.

The FSB said the suspected organisers of the attacks were planning to kill a senior defence official using a remotely controlled car bomb.

Russia has detained a citizen of Uzbekistan who it says has confessed to planting the bomb that killed Lieutenant General Igor Kirillov in Moscow.

Lieutenant General Igor Kirillov was the head of Russia's Nuclear, Biological, and Chemical Protection Troops. Authorities said the explosion was caused by a bomb hidden inside an electric scooter.

Kirillov, who was chief of Russia ’s nuclear, biological and chemical protection troops, was killed outside his apartment building on Tuesday along with his assistant when a bomb hidden in an electric scooter went off. He is the most senior Russian military officer to be assassinated in Russia by Ukraine.

Russia's Federal Security Service said on Thursday it had foiled several plots by Ukrainian intelligence services to kill high-ranking Russian officers and their families in Moscow using bombs disguised as power banks or document folders.