A love triangle turned deadly when a gunman wounded his ex-girlfriend and killed her new suitor early Sunday in East Harlem, according to cops and police sources.

The jilted man opened fire inside a seventh-floor apartment in NYCHA’s East River Houses at around 5:20 a.m., blasting Damian Coleman in the abdomen and Coleman’s girlfriend in the left leg, authorities said.

First responders rushed Coleman, 27, from the public-housing building on East 102nd Street near First Avenue to Metropolitan Hospital Center, but he could not be saved.

Coleman’s 26-year-old girlfriend, whose name was not released, was on the mend at NewYork-Presbyterian Hospital after being wheeled from the building with a bandage wrapped around her lower leg (right).

Investigators did not disclose the 31-year-old suspect’s name as they continued their search for him late Sunday, but sources said that he formerly dated the female victim.

Grieving relatives of Coleman, who lived in another NYCHA complex, Harlem’s King Towers Houses, were too distraught to speak with a reporter on Sunday.

But a neighbor who knew Coleman from around the building said the victim wasn’t one to court trouble.

“He knew a lot of people but he stayed out of the streets,” said the King Towers resident, who would only give his name as Dave. “He was a nice kid.”

As cops scoured the East River Houses for clues, including ballistic evidence, locals were left on edge — but hardly surprised.

“It’s just scary,” said Trista Wong, a resident of the complex for the last six years. “It actually happens quite often.”

Though Coleman’s slaying marked the first of 2019 for the area’s 23rd Precinct, it was the command’s seventh shooting this year, NYPD statistics show.

Through May 19 of last year, the precinct tallied only three shootings.

Similar trends bear out across the five boroughs, which through the same date had measured an 11.7-percent decline in murders but a 1.7-percent increase in shooting incidents, according to department figures.

The 23rd Precinct’s public-housing developments have also seen a 39.2-percent spike in general crime so far this year.

Sunday’s gunplay left some East River Houses residents scared to set foot outside, even with the mercury rising.

“I don’t go out because there’s a lot of violence here,” said Jackie Cruz, 20. “I just want to move out now.”

But others said they’ve come to accept incidents like Coleman’s death as a reality.

“This goes on all the time around here,” said one resident who declined to give his name as he walked into the building with a shrug.

Additional reporting by Larry Celona