The teen flashed a gun as he fought with another youngster inside Hollis Playground at 204th Street and Hollis Avenue in Queens Village around 3:40 p.m., cops said.

The parent, 33, and child were both pronounced dead at the scene. The probe is ongoing.

The feds have opened a criminal investigation into New York City’s migrant hotels — demanding Wednesday that staff turn over names of “aliens” housed at shelters, The Post has learned.

Police shot a maniac after he lunged at them with a box cutter in Brooklyn Wednesday, leaving him clinging to life, sources said.