A 5-year-old Bronx boy shot himself in the arm today while playing with his father’s gun, authorities said.

The child was in an apartment on Westchester Avenue when he wounded himself about 10:30 a.m., cops said.

His father Denny Pantoja, 33, was charged with criminal possession of a weapon and endangering the welfare of a child.

The dad grabbed the kid and rushed him toward the hospital, cops said, but was pulled over for blowing a red light, and an ambulance was flagged down for the child on Third Avenue and Brook Avenue, officials said.