An Uzbek national was offered $100,000 (£78,650) by Ukraine to assassinate the head of the Russian army’s chemical weapons unit, Moscow has claimed.

Russian police have arrested a 29-year-old suspect, who they say had been “recruited by Ukrainian special forces” and offered the money for the assassination of Lt Gen Igor Kirillov.

“On their instructions, he arrived in Moscow, received a powerful improvised explosive device and placed it on an electric scooter, which he parked near the entrance of Kirillov’s home,” Russia’s Investigative Committee said in a statement.

Investigators said the suspect set up a camera in a rental car that broadcast live footage to a Ukrainian SBU intelligence service control centre in the city of Dnipro.

There, an SBU agent “remotely activated” the IED before dawn on Tuesday when Kirillov walked out of his apartment block, killing him and his assistant.