"We do not know with any certainty how long the baby has been there or how it has died and while I understand there will be concern in the community I want to reassure residents that we will be working hard to answer these questions.
"If anyone has any information whatsoever, regardless of how insignificant you think it might be, please get in touch.
"We are obviously deeply concerned for the welfare of the mother and if anyone has seen someone in the area or has any information about who you think the mother might be please call us."
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More than £1.5 million has been raised in the wake of the terrorist attack in Manchester on Monday night.
Chelsea football club has cancelled a homecoming parade to celebrate their Premier League title win.
Twenty-two people, including children as young as eight, were killed and at least 59 injured during the suicide attack.