The Metropolitan Police has told ITV News that 50 people have been temporarily detained as a result of the 'critical mass' procession.
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Another cold night across Britain with temperatures closely dipping below freezing in rural areas in the north.
Investigative journalist Sue Lloyd-Roberts, who worked at both ITN and BBC News, has died after a battle with leukaemia.
A man found his wife of four months dead near her overturned car after he went looking for her when she didn't return home.