One of the country's busiest shopping streets has been closed as a man wearing gas canisters stormed into an office and threatened to blow himself up, it was reported. Tottenham Court Road in central London was closed after police received emergency calls at midday. Scotland Yard sent a hostage negotiator to the scene amid reports the man had held people hostage inside the building several floors up. Pictures emerged of computer and office equipment being thrown through one of the office windows. A police spokesman said it was "too early to say...