The boxes appear to be built to resemble chain linked cages, holding childlike mannequins wrapped in foil.
They were found in front of at least 24 locations in Manhattan and Brooklyn.
Police officers responded, but quickly determined the boxes appears to be political protests that posed no danger to the public.
Witnesses told police a box truck dropped off the protest materials at the various locations.
They are part of the #nokidsincages protest which is being documented on a Twitter account.
Today we launch #NoKidsInCages to protest the separation of children from their families at the border. Support @RAICES to close the 1,700+ new cases. Sharing is an act of protest. https://t.co/0l3vefBShp #PassHR541 pic.twitter.com/MQEKsZpSVI— No Kids In Cages (@NoKidsInCagesUS) June 12, 2019
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