The NYPD trapped over 300 protesters in the Bronx marching for George Floyd and waited until the 8 p.m. citywide curfew to arrest them for breaking the law, a human rights group wrote in a scathing report released Wednesday.

Human Rights Watch said Bronx cops surrounded protesters on June 4 in a tactic known as kettling, refused to let them disperse, then began “whaling their batons, beating people from car tops, shoving them down to the ground and firing pepper spray in their faces” as soon as the curfew hit.

The 8 p.m. shutdown was imposed a few days earlier to stem widespread looting amid marches against the death of George Floyd, who died in Minneapolis police custody.

“As protesters cried out — some with blood dripping down their faces — the police began to arrest them. They forced people to sit on the street with their hands zip-tied behind their backs, at times so tight that their hands went numb,” said Human Rights Watch in their report.

The organization said they questioned 81 protesters and reviewed 81 videos and police scanner calls for the report. They also released a 12-minute video filled with diagrams of the Mott Haven clash, interviews with witnesses and protesters, and cellphone videos taken at the scene.

“We were there to protest police brutality and ironically became victims of police violence," said protester Andom Ghebreghiorgis in a Wednesday press conference.

Police Commissioner Dermot Shea and Mayor Bill de Blasio defended the NYPD’s plan a day after the 312 arrests, with Shea saying it was “executed nearly flawlessly" with Chief of Department Terence Monahan at the helm.

Shea claimed that the same people who organized the Mott Haven rally were behind violent protests earlier in the year, and cops recovered weapons, guns and gasoline at the scene.

But cops later admitted that no gasoline was ever found, and the gun arrested happened three hours before the protest, about half a mile away.

In response to the Human Rights Watch report, the NYPD said it was reviewing its tactics.

“The NYPD has conducted an ongoing review of the department’s response to protests and riots,” the NYPD said in a statement. “Enhanced training and techniques have already been put in place.”

Arrested protesters were issued summonses, but Bronx District Attorney Darcel Clark later said the tickets would be dismissed. More than 100 protesters have since filed notice of claims against the city and plan to sue.

The Human Rights Watch report also noted that the mayor’s office and the NYPD did not seem to be on the same page about who would be exempt when the curfew was announced June 1.

One City Hall staffer confirmed that those "who are doing jail, legal and medical support for arrested protestors” would be exempt from the curfew. But the NYPD arrested some of those “legal observers” during the June 4 chaos, according to the report.

The NYPD’s top lawyer, Legal Matters Deputy Commissioner Earnest Hart, later wrote in a Sept. 16 letter to Human Rights Watch Acting Crisis and Conflict Director Ida Sawyer that legal observers had no such exemption.

Hart also made no mention of the supposed violence in his letter, and said people were simply arrested for violating curfew, Sawyer said Wednesday.

“It was very jarring to see (the videos), and I’ve spent many years in Congo and central Africa documenting crackdowns on protesters," said Sawyer. “This wasn’t on that scale, this was clearly a violation of human rights law.”