PHILADELPHIA (CBS) – Philadelphia police have arrested two suspects and are searching for two others for their roles in a violent attack that left a man unconscious in a popular nightlife district.

Michael Russo and Edward Costello were apprehended for their alleged roles in the attack that occurred April 30 at about 2 a.m. in the 100 block of Chestnut Street in the Old City section of Philadelphia.

According to investigators, the incident began when two groups of men became involved in a verbal argument at the Mad River Bar.

The altercation then spilled out into the E-Z Park lot located at 100 Chestnut Street.

Surveillance video shows a group of men begin to assault one man. A second man, a 27-year-old son of a Philadelphia police officer, then intervened to assist the first man that was being attacked. The group then turned their attention to the 27-year-old and began assaulting him.

As the attack stopped momentarily, one the suspects is seen walking up to the victim and sucker-punching him. The victim fell to the ground and was knocked unconscious as a result of the violent punch. He suffered a broken jaw, a fractured left orbital bone and six stitches to his forehead.

The suspects fled the scene as the victim was assisted by a witness. Following an investigation and tips from the public, Russo and Costello were arrested.

Police are still searching for the two other suspects involved in the attack.

Anyone with information is urged to call 215-686-3093/94 or 215-686-TIPS (8477).

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