No evidence to link London attack directly to militant groups - U.S. sources

By Mark HosenballLONDON (Reuters) - British police and spy agencies have not found evidence that last week's attack on a London commuter train was ordered or organised by a recognised militant group, according to U.S. and British government sources familiar with the investigation.Counter-terrorism officers have arrested two men after a crude homemade bomb sent flames shooting through a packed carriage at west London's Parsons Green underground station during the Friday morning rush hour, injurin