Knives were recovered and 46 people were searched under Section 60 powers after the 13-year-old boy was stabbed near Grand Central on Wednesday.
The operation followed the stabbing near McDonald’s in Stephenson Place. His injuries were not life-threatening.
Two 16-year-olds arrested in connection with the stabbing have since been released on bail with strict conditions.
West Midlands Police said it worked in partnership with British Transport Police to conduct weapon sweeps, resulting in two knives being recovered near New Street Station after stepping up patrols in recent days.
In addition to recovering weapons, three youths were made subject to Community Protection Warnings for persistently causing problems.
The force stated: "We understand the use of these powers can cause concern and seem excessive. We use these powers to protect the public from further violence.
"Our priority is to keep you safe."
"We will be continuing to provide reassurance patrols around the city centre over the weekend alongside our colleagues at British Transport Police, and working with youth workers to engage with the public and reduce knife crime."
Witnesses to the stabbing should send information, photos and videos that can help the investigation to mipp.police.uk/operation/20HQ21C40-PO1