Speculation not helpful, British PM May tells Trump after attack tweet

British Prime Minister Theresa May said on Friday it was not helpful for anyone to speculate on investigations after U.S. President Donald Trump tweeted that the culprits behind a train bombing had been "in the sights" of the police.Soon after 22 people were injured in the attack on a busy underground train in west London, Trump tweeted: "Another attack in London by a loser terrorist.Asked whether Trump knew something Britain did not, May said: "I never think it's helpful for anybody to speculat