Click here to watch the surveillance video of the attack.

CHICAGO – Authorities are investigating claims that six off-duty Chicago police officers were captured on video assaulting four men in a bar, the second incident involving taped allegations of violence by off-duty officers to surface in the past week.

After the alleged Dec. 15 incident at the Jefferson Tap and Grille, one of the four men required reconstructive surgery for a broken nose and another had broken ribs, said Steven Fine, an attorney for the men.

Police and the Cook County state’s attorney’s office are looking into the claim, said police spokeswoman Monique Bond, who declined to discuss details. No charges have been filed in the case, a department spokesman said Sunday.

Adam Mastrucci, Scott Lowrance and brothers Aaron and Barry Gilfand were playing pool at the bar when the off-duty officers attacked them, Fine said.

Patrol officers responded to a 911 call, but allegedly left after speaking to one of the off-duty officers, Fine said.

“I don’t think this is a case where the police department can say they don’t know who they’re looking for,” Fine said.

Security cameras inside and outside the bar captured the incident, said Sally Saltzberg, another attorney for the men.

Saltzberg filed a petition Feb. 27 in Cook County Circuit Court seeking the officers’ names, a precursor to a lawsuit. The men have not formally filed suit. The petition is scheduled to appear before a Cook County judge on April 2.

The latest claims follow accusations that another off-duty police officer beat a female bartender who refused to him serve drinks. That attack was recorded on a bar surveillance camera.

Karolina Obrycka was punched, kicked and thrown to the ground in the attack at Jesse’s Short Stop Inn on Feb. 19.

The Chicago Police Department is looking into whether police acted properly while arresting Anthony Abbate, a 12-year police veteran, who is charged with felony aggravated battery. He has been put on leave pending an internal investigation, and Bond has said she expected the department to fire Abbate.