A woman had been pushing her child in a pram when she stopped to get some money from the ATM machine, close to Tesco Express in Heysham Road at around 6.30pm on Wednesday (April 13).
The woman reached under the pram and when she looked up, she was confronted with a man holding her 20-month-old daughter in his arms.
The mum screamed, grabbing back the child and the man fled from the scene, running through an alleyway behind the Tesco store.
The baby was not injured and no arrests have been made. Detectives say they do not know the man’s motives at this stage but described the incident as “very concerning”.
Officers have conducted a number of CCTV and investigative enquiries and are now appealing to the public for information.
Det Insp Andy Ellis, of Lancaster CID, said: “This is clearly a very concerning incident and we want to identify the man involved as soon as possible.
“Thankfully both mother and daughter were unharmed.
“It would appear at this stage the man has just held the child, as opposed to attempting anything more serious, however, this is clearly worrying.
“If you saw what happened, or anyone acting suspiciously in the area around the time of the incident, please come forward immediately.”
If you can help call 101 or email [email protected] quoting log number 1141 of April 13.