A 16-year-old boy was shot and killed while walking with his girlfriend in Brooklyn on Wednesday afternoon, sources said.

The teenager was on Macon Street in Bedford-Stuyvesant when he exchanged words with a 17-year-old male at around 2 p.m., according to law enforcement sources.

As he began to walk away, the 17-year-old turned around and fired one shot — striking the teenager once in the head, sources said.

The 16-year-old was taken to Kings County Hospital, where he died, sources said.

A person of interest was taken into custody and being questioned at the 81st Precinct Station house on Wednesday evening, according to police.