An off-duty cop already on modified duty assaulted a female subway conductor aboard a Manhattan J train during morning rush hour Wednesday, sparking pandemonium among subway commuters who abandoned their belongings and ran for safety, officials and witnesses said.

The conductor opened the door to her booth in the middle of the train around 8:50 a.m., striking the off-duty officer with the door, as the train was pulling out of the Delancey Street-Essex Street station, police said.

The cop, identified by sources as Tremel Davis, 33, of Brooklyn, got into an argument with the conductor and shoved her to the floor, cops said.(nypost.com)…[+]