UNITED STATES—On July 15 at 10:10 a.m., officers of the New York Police Department (NYPD) including its Chief of Department, Terence Monahan, were brutally injured by protesters crossing the Brooklyn Bridge.

At 12:54 p.m. NYPD tweeted a video of the attack with the caption, “Three officers violently attacked by protesters crossing the Brooklyn Bridge. The officers sustained serious injuries. This is not peaceful protest, this will not be tolerated.”

The video shows three officers appearing to be in the midst of detaining an individual when people from the bridge start tugging at them through the rails while an unidentified suspect started beating them with what looks to be a striking stick.

Another video released by NYPD shows the extent of the injuries:

Police Commissioner for NYPD, Dermot Shea, commented on Twitter. “Three of our officers were brutally attacked by protestors today. These are the conditions your officers have to operate in every day while they continue to protect your neighborhoods. Such assaults are ALWAYS unacceptable, and should outrage us all.”

Police reported a total of eight officers who suffered injuries that ranged from cuts to a broken orbital bone. 37 protesters were arrested, some of whom also took part in assaulting the officers. Shaborn Banks, 25, allegedly punched a lieutenant, resulting in a broken eye socket, while another individual, Quran Campbell, 25, has been charged with assaulting three officers.

The man shown beating officers with the stick fled the scene and remains at large and wanted for the assault. Crimestoppers released these video details of the perpetrator:

The NYPD officers were there marching alongside a pro-police group while protesters were there in support of the Black Lives Matter movement that has recently been pushing the agenda of defunding police departments across the board. Mayor Bill de Blasio was to hold a conference later that day to sign a new order of police accountability laws.

Monahan kneeling alongside protesters.

One of the injured included Monahan, who has been on the force with NYPD for 35 years and as Chief he oversees 40,000 uniformed men on the job. Monahan kneeled during a protest on June 1 and held hands with others. A fellow protester stated to Monahan, “Thank you for supporting us,” before embracing him.

Authorities are still seeking any information on the assailant. They ask the public to direct message @NYPDTips or call 800-577-TIPS. All calls will be anonymous.