UPDATED 2/14/11 10:30 p.m.

CHICAGO (CBS) — One of two teens injured after being shot on the Southeast Side flagged down a CTA bus Monday afternoon near South Shore High School.

The shooting happened about 2:50 p.m. at 75th Street and Constance Avenue, according to police News Affairs Officer Daniel O’Brien.

Two male teens were shot and both were hospitalized in serious to critical condition, Fire Media Affairs Dir. Larry Langford said. One was taken to Northwestern Memorial Hospital, the other to Advocate Christ Medical Center.

A spokeswoman for the Chicago Public Schools confirmed that both victims were students at South Shore High at 7529 S. Constance. The shootings occurred at a bus stop near the school. One victim was 17 and another was 18.

Initial reports said the teens were shot on a CTA bus, but CTA spokeswoman Catherine Hosinski said the shootings were not on the bus. At least one of the wounded teens flagged down a westbound No. 75 bus after being shot. The driver stopped and called police, she said.

CBS 2’s Mike Parker talked with the mother of one victim, who was shot in the leg. She said he was doing well, and that the young man’s friend, the other victim, had been shot twice.

Police say the shooter ran down an alley and disappeared.  Investigators say it’s possible the gunman could be identified by a police surveillance camera mounted just across the street. Also, a camera on the bus may yield some information.

“Turn yourself in,” community activist Andrew Holmes said. “There’s two cameras out here and we do have witnesses.”

LISTEN: Newsradio 780’s Steve Miller Reports

Engine 72 responded to a report of a person shot on the bus, Langford said. But fire personnel later learned the person was not shot on the bus. “He was pulled onto the bus as a refuge,” Langford said.

In the wake of the shooting the street was blocked off by police and the No. 75 bus rerouted around the scene, according to a CTA customer alert on the agency’s website. By 5 p.m. the street blockage had ended and the No. 75 bus was back to its regular route, Hosinski said.

Contributing: Sun-Times Media Wire

Watch & Listen LIVE