A press conference being used by police to spruik new crime-busting cameras has been interrupted when the technology detected several wanted people.

A woman who allegedly failed to appear in court was among three people picked up by the real-time facial recognition cameras at the Mirrabooka bus station in Perth’s north on Thursday afternoon, forcing officers into action.

WATCH THE VIDEO ABOVE: Arrests made as new cameras spark police into action

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“Been happening all week,” WA Police Commissioner Col Blanch said.

“I’d love to say I planned that, but I think that’s exactly what the technology is.

“People are being arrested because they are wanted.”

New cameras have helped WA Police pick up a wanted woman during a press conference spruiking the technology. Credit: 7NEWS

Police made three arrests during a press conference in Perth. Credit: 7NEWS

More than 130,000 faces were scanned during the opening week of the Australia-first trial, starting June 22, and 18 arrests were made.

Sixteen of those arrests related to outstanding warrants, and two were for breaching exclusion orders in entertainment precincts.

“If we’ve got 4000 people in our community with arrest warrants, no one should be happy with that,” Blanch said.

“If this can solve most of those problems, I think it’s a great deal.”

The cameras also helped police speak to two people for welfare checks.

The cameras are mounted on or near a marked WA Police van, and scan crowds to instantly detect faces and compare them against targets or people banned from certain areas.

If the technology sounds the alarm, a human makes the final assessment on whether there is an actual match.

The commissioner said “we have a human in the loop” to double-check false starts.

The Overt Live Facial Recognition technology will be mounted on or near a marked WA Police van. Credit: 7NEWS

An officer in a van determines if there is a match. Credit: 7NEWS

Images of community members not on the alert list are automatically pixelated and deleted.

“Speaking to the team who have been setting this up for the last week, the overwhelming positive feedback from our community has been great to receive,” Blanch said.

“That doesn’t mean people haven’t come up and showed concern, they have.

“But they’ve asked questions, they’ve had sensible discussions about what it does do and what it doesn’t do.”

The WA trial will run for five months, but authorities are already impressed.

“I think the results send a very strong message about the effectiveness of this technology,” WA Police Minister Reece Whitby said.