Updated 3:25 p.m.
A boy and a girl hanging out with a group of fellow students in a high school gym were shot and wounded Friday afternoon, and up to three other boys may have been involved in their shooting, police said.
One boy fled and was captured near his home, and one or two other boys were being sought, they said.
The shooting happened at the Delaware Valley Charter High School in north Philadelphia around 3 p.m., authorities said.
Surveillance video shows a group of about seven students hanging around when the shooting happened, police Commissioner Charles Ramsey said. It was unclear if the shooting was accidental or intentional but it "doesn't look like an active shooter type of situation," he said.
The wounded boy and girl each were shot in an arm, but it was unclear whether one or two shots were fired, Ramsey said. The wounded students, believed to be 15 years old, were taken to a hospital near the school, where they were listed in stable condition, police said.
The boy who was captured lives miles away from the school in south Philadelphia and may have driven or taken a bus home after the shooting, Ramsey said. No gun was recovered, he said.
"We have not found a gun, but there's two, perhaps three, youngsters that were together," Ramsey said. "We're not sure which one fired. One of the ones that we have was part of that group. They're all boys, all students."
Ramsey didn't know what staffing or security procedures were in place at the school but said "there was a breakdown in security of some kind" because the gun got into the building.
The school was placed on lockdown and secured by SWAT officers checking each room. Students were searched and released one by one.
A spokesman for the school district didn't immediately respond to a call seeking comment. The president of the charter school's board of trustees said he didn't have any additional information about the shooting, not the only U.S. school shooting this week.
Authorities said a seventh-grader opened fire Tuesday in a New Mexico middle school gym, wounding two classmates.
--AP's Maryclaire Dale
Police say two students have been shot at a Philadelphia high school and the shooter may have been a fellow student and is on the loose, according to the Associated Press.
They say the shooting happened late Friday afternoon at the Delaware Valley Charter School in north Philadelphia.
Authorities say a male student and a female student were shot, AP reported. Each student was shot in an arm.
The students have been taken to a hospital near the school. Police say they're in stable condition.
Police say the school has been placed on lockdown and is secure, according to NBC10 in Philadelphia. Officials say students are being searched and then released on a one-by-one basis.
Police Inspector Joe Sullivan tells KYW-TV it's unclear whether the shots were fired from inside or outside the school.
Police are still searching for the person or persons responsible and no one is in custody, NBC10 reported.
A spokesman for the school district hasn't responded to a call seeking comment.