In March 2018, former Russian double agent Sergei Skripal and his daughter Yulia were victims of a nerve agent attack in Salisbury in the United Kingdom. The nerve agent, identified as Novichok, caused significant bodily harm to both Skripal and his daughter, as well as to Detective Sergeant Nick Bailey. The police believed that two Russian nationals going by the aliases Alexander Petrov and Ruslan Boshirov were responsible for the Novichok attacks. The men claimed that they were in Salisbury as tourists, but the Bellingcat investigation team produced several in-depth reports tying them conclusively to the GRU, Russian military intelligence. In response to the incident, British Prime Minister Theresa May announced the expulsion of 23 Russian diplomats from the United Kingdom, triggering similar actions from other European allies. In August 2018, the United States imposed its own sanctions on Russia as a result of the Novichok attack.