A fight among a group of high school students in Oxford Circle on Wednesday afternoon left a 16-year-old in critical condition after an 18-year-old pulled out a gun and shot him several times, according to police.

The alleged shooter was in custody but had not yet been charged, Homicide Capt. John Ryan said Thursday.

Police did not identify the shooter, and said charges would depend on whether the victim — whom police also have not identified — survives.

Ryan said police caught the suspect because an officer in the area saw the shooting and chased down the alleged gunman.

Police still were trying to determine what the teens may have been fighting over, but Ryan said there was "nothing that can be justified" about the incident around 4:25 p.m. on the 2100 block of Magee Avenue.

According to Ryan, the incident — some of which was captured on video — began as a confrontation among teens. The alleged shooter pulled out a gun, and "one of the people involved in the fracas ends up getting shot," the captain said.

The victim suffered several gunshot wounds to his head, police said. He was taken to Aria Health-Torresdale Campus and placed in critical condition.