Humberside Police have said they are considering the possibility that the "mosque was targeted for racial reasons," but stressed that it would not be fair to speculate on this at present.
They said there was was "no suggestion" of a link between two separate offences - a fire at the mosque last night, and reports of youths damaging the building on Thursday.
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A 25-year-old man has been arrested in Newport, South Wales, in connection with the Parsons Green terror attack, Scotland Yard said.
A milder night ahead with some cloud low enough to be misty in places.
Tata Steel and Thyssen Krupp will formally announce the merger of their European steel operations on Wednesday, ITV News understands.