The search for a missing Mount Vernon teen with autism has expanded into the Bronx.

Jonathan Bryant, 15, was last seen on Thursday afternoon on Vernon Avenue in Mount Vernon. His mother reported him missing at around 1 a.m. Friday when she came home from work and found him gone. Police say the boy has a fascination with trains and in the past had gone missing and was later found in train and subway stations in New York City.

A favorite spot of his is Bay Plaza in the Bronx and police spent Monday handing out fliers, hoping to find clues to where he is. Possible sightings were reported in Manhattan and Queens, but nothing has been confirmed.

Bryant was last seen wearing a Cozumel T-shirt, white shorts and red and black sneakers. He is not on medication and is fully functional.