Ricin the attack on Georgi Markov another Bulgarian defector, Vladimir Kostov, survived a similar attack. Kostov was standing on an escalator of the Paris metro when he felt a sting in his lower back above the belt of his trousers. He developed a fever, but recovered. After Markov's death the wound on Kostov's back was examined and a ricin-laced pellet identical to the one used against Markov was removed. Several terrorists and terrorist groups have experimented with ricin and caused several incidents of the poisons being mailed to U.S. politicians. For example, on May 29, 2013 two anonymous letters sent to
London Buses route 7 and London Bridge station. This route disappeared later in 1916 owing to Wartime shortages, but reappeared on 30 April 1917. During the 1920s, route 7 was extended to Acton and a 7B was introduced as a Waterloo station to London Bridge, Monday to Friday peak hours only service via Holborn. On 1 December 1924, a new system of route numbering on London buses came into force under The London Traffic Act 1924. This gave the Metropolitan Police responsibility for bus operation and route numbering. Route 7 remained unchanged; the 7A was renumbered 107, and the 7B to 166. Short workings