A maniac allegedly pistol-whipped a female postal worker in an attempted robbery of a post office in East Harlem, the NYPD said Friday night.

Cops were called the Hellgate Station post office at 153 E. 110th Street just after 6:15 p.m.

According to police reports, a man reportedly entered the post office carrying a gun with the intention of robbing the federal building. During the incident, he is believed to have used the weapon to hit a 51-year-old woman on the head and demanded money from her.

However, the suspect fled empty-handed on a bike.

The victim was treated at the scene for her injuries and did not require further medical attention, the NYPD said,

No arrests have been made, and an investigation is ongoing.