Vigilante gunman on the loose after opening fire on homeless man trying to rob woman in Times Square subway station

A vigilante gunman is on the loose after opening fire on a homeless man trying to rob a woman in a Times Square subway station, police said Wednesday.

Nobody was struck when shots rang out inside the 49th St. station about 10 p.m. Tuesday.

The mugger was holding open an emergency exit gate near the turnstiles when he told a 40-year-old woman if she didn’t hand over money he’d steal her purse.

That caught the attention of the gunman.

“Leave her alone,” the vigilante said, then fired twice, thwarting the robbery attempt, according to police. The gunman got away and is being sought..

Police arrested 40-year-old Matthew Roesch for the mugging. He was charged with attempted robbery.

Roesch, who has been staying at a homeless shelter by Bellevue Hospital, has one prior arrest, for theft of service at the Times Square-W. 42nd St. stop on Sept. 18.

The gunman is described as light-skinned and in his 40s. He wearing black shorts and a green shirt.

Anyone with information is asked to call Crime Stoppers at (800) 577-TIPS. All calls will be kept confidential.