Police hunt possible bomb-maker, accomplices after Manchester bombing - sources

By Michael Holden and Andy BruceMANCHESTER, England (Reuters) - British police hunted on Wednesday for potential accomplices who may have helped Salman Abedi build the bomb that killed 22 people in a crowded concert hall in Manchester and who could be ready to kill again.As police tried to piece together the British-born Abedi's past, Prime Minister Theresa May said security officials had raised their assessment of the threat to Britain to "critical", indicating an attack was imminent.Part of th