A man has been arrested in connection with the assassination of the head of Russia’s chemical, radiological and biological weapons unit, Lt. Gen. Igor Kirillov, authorities in the country said Wednesday. “During the interrogation, he explained that he was recruited by the Ukrainian special services,” Svetlana Petrenko, a spokesperson for Russia’s Investigative Committee said in a statement. “On their instructions, he arrived in Moscow and received a homemade explosive device. He placed it on an electric scooter, which he parked at the entrance to the residential building where Igor Kirillov lived,” she added.   The suspect rented a car and “installed a video surveillance camera,” so he could broadcast the footage online, Petrenko said, adding that he was from Uzbekistan and in his twenties. The suspect, who authorities did not name, was identified by state media citing footage from the FSB — Russia’s domestic intelligence agency — as Akhmad Kurbanov. Petrenko said he was was guaranteed $100,000 and European residence as payment for the attack, which also killed Kirillov’s assistant Ilya Polikarpov. The Security Service of Ukraine (SBU) had already claimed responsibility for the attack on Tuesday. Video published on Telegram by Russia’s Investigative Committee on Tuesday showed emergency responders parked outside an apartment building where one entrance could be seen visibly damaged. Kirillov was killed the day after he was charged by Ukrainian security services with the use of banned chemical weapons during Russia’s invasion of the country, which in February 2022. Russian authorities have denied those allegations. His death is the latest in a string of such attacks. Last month, the SBU claimed they had assassinated Valery Trankovsky, a Russian naval captain in charge of a brigade missile ships in the Black Sea, after his car was blown up. Citing Ukrainian media, the Associated Press also reported that Sergei Yevsyukov — the former head of a prison housing Ukrainian POWs — was killed by a car bomb in Russian-occupied Donetsk earlier this month. Kirillov had also been sanctioned by Britain in October, with U.K. authorities punishing the general and Russia’s nuclear protection forces for the use of riot control agents and reports of the use of chloropicrin, a chemical choking agent, on the battlefield. In a statement at the time, the British government said Kirillov was “responsible for helping deploy these barbaric weapons” and had also been “a significant mouthpiece for Kremlin disinformation, spreading lies to mask Russia’s shameful and dangerous behavior.” But shortly after his death, Russian Foreign Ministry spokesperson Maria Zakharova defended Kirillov, who also held several posts in the Directorate of the Chief of Radiation, Chemical and Biological Defense since 2009 before leading the force, according to state news agency, RIA.  “He worked fearlessly,” Zakharova said in a statement published to Telegram. “He met problems head on. For the Motherland, for the truth. Bright be his memory, may he rest in peace.” She added that he had been “systematically exposing the crimes of the Anglo-Saxons for many years.”  The killings have come during a period in which Russian forces have gained momentum in the country’s war with Ukraine, pushing forward in the east of the country. However, Ukrainian special forces said Tuesday they had killed 50 North Korean troops in Russia’s Kursk region, marking the first such casualties since the secretive communist state sent soldiers to eastern Europe. Pentagon Spokesperson Maj. Gen. Patrick Ryder also said Monday that North Korean military personnel have been killed and wounded in combat operations in the area but did not specify how many casualties they had suffered.  This story first appeared on NBCNews.com. More from NBC News: Luigi Mangione indicted on first-degree murder charge in UnitedHealthcare CEO’s killing Ukraine claims it assassinated Russian general in charge of chemical and nuclear weapons A veteran’s corpse was sent across state lines — before his family knew he was dead