The ominous mailing, reported to the NYPD around 2:40 p.m. Monday, included an assortment of newspaper clippings with random letters and symbols written in red, the sources said.

A swastika was scrawled on the forehead of an unidentified man depicted in the news cutouts, according to the sources.

The letter did not include any specific threats, the sources said. Its origin is unclear.

The NYPD is investigating the letter as anti-Semitic harassment, according to the sources.

The Post has reached out to Sirius XM for comment.