A visibly angry NYPD Commissioner William J. Bratton announced Monday night that the search is on for six people wanted in connection with the weekend assault of two police lieutenants on the Brooklyn Bridge during a protest march.

Bratton, accompanied by high-ranking members of the NYPD, said at a news conference that the six suspects, three males and three females, were identified from YouTube videos of an altercation between demonstrators and the two police lieutenants. The NYPD Tuesday will release sharper images of the six accused of assaulting the pair of cops, identified by NYPD officials as Lt. Patrick Sullivan and Lt. Phil Chan.

Sullivan sustained facial contusions, and Chan's nose was broken in the altercation, Bratton said.

"They were in the course of making a lawful arrest. They were interfered with. They were beaten," Bratton said of the two police officers.

Bratton's comments came after other NYPD officials said earlier Monday that they don't expect major changes in the way the police department handles large demonstrations in the aftermath of the recent wave of protests.

Bratton said that since Dec. 3, when a Staten Island grand jury declined to indict an NYPD officer in the apparent chokehold death of Eric Garner, the city has spent nearly $23 million in overtime for police officers dealing with almost nightly demonstrations.

Sunday night's Brooklyn Bridge protests included the arrest of Eric Linsker, 29, of Brooklyn on charges of assaulting a police officer and resisting arrest in connection with the altercation with the lieutenants.

NYPD officials said video shows Linsker, a Baruch College English professor, resisting arrest and punching one of the lieutenants. Linsker appeared in court Sunday night before being released on his own recognizance.

The plainclothes officers, from the department's legal bureau, wore NYPD jackets identifying them as police, Bratton said.

"We are here to protect the constitutional rights of demonstrators, but when agitators claim to take over, we will be there to stop them," Bratton said. "Our intent is to arrest all these individuals, and we anticipate strong cooperation from the public."

Mayor Bill De Blasio at an unrelated Brooklyn news conference asked that anyone with information about the individuals who attacked the police officers "come forward with that information."

He condemned violence toward police officers and said Linsker should be removed from his post if found guilty.

"It is incumbent upon all those who are protesting to set a high standard, to respect the police who have done such a fine job of protecting them and working with them," de Blasio said. "An attack on a police officer goes against the grain of our civilization."

Earlier yesterday, Stephen Davis, NYPD deputy commissioner of public information, said the department will not make major changes in the way it handles protests.

Davis said changes in policing will occur on the ground as events unfold such as the number of protesters, or the direction of the march, he said.

"Any changes will be ad hoc in nature and made by our local commanders as situations change," he said.

With Emily Ngo and

Lauren R. Harrison