Following an alleged altercation early Sunday morning in the parking lot of the Zeta Psi fraternity — located near Durant and Piedmont avenues — Frank Watson, 23, was charged Monday with two counts of attempted murder and two counts of assault with a deadly weapon.

Watson allegedly struck two men in the head with a baseball bat, causing them to collapse, Berkeley Police Department Officer Jason Muniz wrote in an affidavit. Watson is unaffiliated with the campus, and it is currently unknown whether the victims are UC Berkeley students.

Earlier in the night, a group of white men and a group of black men were verbally arguing in the parking lot and exchanged punches, the affidavit said. Witnesses told Muniz that a silver hatchback pulled up across the street, and the group of black men walked toward the vehicle. Watson left the suspect vehicle and grabbed a baseball bat from its trunk, the affidavit said. Watson then allegedly struck a man across the head without warning. Another man approached Watson, and Watson allegedly struck him across the head, too. Both victims immediately collapsed to the ground, the affidavit said.

At 1:25 a.m., BPD received an assault with a deadly weapon report. Muniz wrote in the affidavit that when he and other BPD officers arrived on scene, he observed a victim lying on the ground with a large amount of blood on his face and possible bleeding from the back of his head. Witnesses directed Muniz to another victim, who appeared to be incoherent with possible head trauma.

Witnesses told officers the suspect vehicle had fled southbound on Piedmont Avenue prior to their arrival. An officer pursued the vehicle and detained Watson with the aid of additional officers, the affidavit said. The front seat passenger fled westbound on Parker Street, the affidavit said. Police officers searched for the passenger but could not locate him.

Witnesses on scene identified Watson as the man who struck the two victims with a baseball bat, the affidavit said. Muniz conducted a records check, which showed a prior arrest history for weapon-related charges and that Watson was on active probation.

The UC Berkeley chapter of Zeta Psi became unaffiliated with the campus in December 2010 after repeated risk-management violations, fire- and life-safety violations, social-code violations and noncompliance with prior sanctions.

Watson, who resides in Oakland, is currently being held without bail in Santa Rita Jail. His plea hearing is scheduled for Friday at 9 a.m. in the Wiley W. Manuel Courthouse in Oakland.