Greater Manchester Police also said a 20-year-old man has been arrested on suspicion of possessing abusive images.
It follows a search at an address in Salford where police also found a suspicious device on Thursday.
The man has been bailed pending further enquiries.
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The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.