Cheshire Police worked with security staff and shoppers at Runcorn Shopping City on Saturday.
A man was arrested by officers after being seen ‘acting suspiciously’, and he is in custody.
Police have thanked those involved for their efforts and are encouraging people to report any suspicious behaviour.
The force’s Runcorn Police team said: “Sergeant Dickin, of Runcorn’s Beat Management team, intercepted and arrested a male seen acting suspiciously in Shopping City.
“Due to the teamwork displayed by the public, security at Shopping City, and Runcorn Police, another potentially lethal weapon has been removed from the streets.
“A suspect has been swiftly located, arrested and is now in custody to answer some uncomfortable questions.
“Reducing knife crime in our community is everyone’s business, and a priority for Cheshire Police through Operation Sceptre.
“If you have any information relating to people carrying knives, then please report this anonymously on 101 or complete a residents voice online survey.”