The U.K. on Friday sanctioned Russian military intelligence units and officers it said were behind preparations for a 2022 bomb attack on a theater in southern Ukraine that killed hundreds of civilians.

Britain’s foreign ministry said it sanctioned 18 officers working for Russian military intelligence, known as the GRU, along with three units. It said the officers were also accused of targeting the family of a former Russian spy who was later poisoned in the U.K. with a nerve agent.

More than 70 different attacks since 2022 have been attributed to Russia by Western officials who say the goal is to sow chaos across Europe, undermine European societies and support for Ukraine.