NYPD Commissioner James O’Neill ordered an investigation Monday into the officers caught on video yanking a baby from his screaming mom — as new footage showed her clinging to the boy’s shirt with her teeth.

“The video obviously is very disturbing,” O’Neill said of the clip that captured officers in a tug of war with Jazmine Headley over her 1-year-old son Friday in a Brooklyn benefits center.

“It’s very disturbing to me also — I’m a dad, I have two kids.”

O’Neill said the department has opened an “investigation” — which will be conducted both by the Internal Affairs Bureau and by borough commanders.

He said they will review cellphone and police body-cam footage of the incident — and piece together what happened before 84th Precinct cops got to the already chaotic scene at the Bergen Street building in Boerum Hill around 1 p.m. Friday, O’Neill said.

Headley, a 23-year-old single mom, was at the center that day because she learned that a child-care benefit had lapsed, and she brought along her son, Damone Buckman III.

She arrived at 9 a.m. to find the building packed, and was forced to stand for nearly four hours with the 17-month-old because there were no open chairs, according to Lisa Schreibersdorf of Brooklyn Defenders, which is representing Headley.

When Headley sat down on the floor to rest her legs, a security officer for the city’s Human Resources Administration — which oversees the site — ordered her to either get up or leave the building.

Headley refused and HRA officers called the cops. But before they arrived, the guards “initiated physical contact” with Headley, a law-enforcement source told The Post.

When officers did arrive, the situation only became more tense.

“It was a violent encounter where the child was being used as a pawn,” Schreibersdorf said.

As horrified onlookers screamed and recorded the chaos on their cellphones, cops and at least one HRA officer fought to wrest Damone from his mother’s arms, the troubling video shows.

“You’re hurting my son!” Headley repeatedly shrieked as she clung to Damone, in one desperate moment clenching the tot’s shirt between her teeth as NYPD and HRA officers tried to pull her away.

One NYPD officer at one point pulled out a stun gun, though it was not discharged.

“I understand you have to use force in certain situations, but this situation was not that situation — especially when there was a baby involved,” said Headley’s mom, Jacqueline Jenkins, who works as a security guard.

“They could have broken her arm, and they were grabbing him like a rag doll.”

When the dust settled, Headley was cuffed and charged with resisting arrest, obstructing governmental administration and acting in a manner injurious to a child.

Headley remains behind bars on Rikers Island because of a New Jersey arrest warrant for failing to appear on a credit-card fraud charge in July 2017.

A judge also issued an order of protection barring Headley from seeing her son, given the nature of the charges.

HRA announced late Monday that two peace officers involved in the incident are on leave, and would be placed on modified duty pending its own investigation.

HRA Commissioner Steven Banks said he was “deeply troubled” by the incident, and also ordered “refresher de-escalation trainings” for its officers and security staff.

Brooklyn Borough President Eric Adams — a former NYPD captain — ripped the officers for their handling of the situation.

“The mother didn’t endanger the welfare of the child,” he said outside the benefits center. “The actions of the department endangered the welfare of the child.”

Adams was not alone in his criticism.

“This was a disturbing incident. Like anyone who’s watched this video, I have a lot of questions about how this was handled,” tweeted Mayor de Blasio. “NYPD & HRA will get to the bottom of what happened.”

Patrolmen’s Benevolent Association President Patrick Lynch said: “These police officers were put in an impossible situation. They didn’t create the dispute at the HRA office.”

City Council Speaker Corey Johnson wants a review of HRA procedures.

“It is unacceptable that . . . HRA has such little capacity to handle its core functions that folks seeking their assistance must sit on the floor with their children while waiting for an appointment,” he said.

“Furthermore, none of this would have happened had HRA security officers handled the situation appropriately from the outset.”

Additional reporting by Shari Logan, Larry Celonaand Tina Moore