首都警察
Police in Manchester were aware that their Metropolitan Police colleagues in London were investigating a suspected IRA unit based in the capital, and wondered whether the London unit was responsible for the Manchester bombing. On 15 July, Metropolitan police arrested six men suspected of IRA membership: Donal Gannon, John Crawley, Gerard Hanratty, Robert Morrow, Patrick Martin, and Francis Rafferty. Each was tried and convicted of "conspiracy to cause explosions at National Grid electricity stations", and sentenced to 35 years in jail. Police in Manchester meanwhile worked to establish if the men were also responsible for the Manchester bomb.