British police have identified more than 200 witnesses and are looking at more than 240 pieces of evidence in their investigation into a nerve agent attack on a Russian ex-spy and his daughter, UK interior minister Amber Rudd said on Saturday. Ms Rudd told reporters after chairing a meeting of the government’s Cobra security committee that more than 250 counter-terrorism police were involved in the investigation, which was proceeding with “speed and professionalism”. Former double agent Sergei Skripal (66) and his daughter Yulia (33) have been in hospital in a critical condition since Sunday, when they were found unconscious on...