Staff discovered the body of a newborn baby at a waste management site on Valley Road, in Bradford last night.
West Yorkshire Police said they have "serious concerns" about the health of the baby's mother and have appealed for her to come forward.
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A band of heavy, thundery showers continues to move northwards through this evening, dying away overnight.
The Duke of Cambridge also laid a wreath to honour the victims before kick-off.
The mother of one of the Manchester attack victims has told of the distressing moment she found her daughter being treated after the attack.