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Savvy shoppers spotted the Stratford-born teen around noon. Delighted fans said the singer tried on swim shorts and sunglasses.
"We were just shopping around the mall and my friend noticed that he walked by," said shopper Chante Gratton. "We decided we were going to follow him and see what he was doing."
News of Bieber's trip quickly spread through the mall and a crowd gathered to see the star.
Staff members at Fairview Park Mall said they had no idea Bieber was planning a visit to the mall. Once they found out, security measures were put in place to control the crowd and protect the star.
Bieber was eventually escorted out of the mall through a back entrance.
CTVNews