Police received a report of a stabbing in Tynwald Road at around 12.10pm on Wednesday (February 9).
A man in his 60s was found with a stab wound to his chest when officers arrived.
He was taken to Manchester Royal Infirmary in a "serious but stable condition", officers said.
A spokesman for Lancashire Police said: "Work is ongoing to establish the exact nature of how the man came about his injury.
"Nobody has been arrested."
Anyone with information can call police on 101, quoting log number 0612 of February 9.
Alternatively, independent charity Crimestoppers can be contacted anonymously on 0800 555 111 or online at crimestoppers-uk.org.
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