By Elizabeth Daley

PITTSBURGH, Pennsylvania (Reuters) - Three teenage boys were wounded on Wednesday and five people have been taken into custody after shots were fired outside a Pittsburgh high school in an incident that police said could be related to a fight that took place at the school a month ago.

The three victims, one age 16 and two age 17 were not cooperating with investigators, police said. Pittsburgh's EMS chief, Mark Bocian, said their injuries were not life-threatening.

"This whole incident ... may have been related over something that happened a month ago," said Pittsburgh police spokeswoman Diane Richard after speaking with officials at Brashear High School, near which the shooting took place.

Richard said a fight at the school on October 18th "quite possibly could be drug-related."

Police took five people into custody late Wednesday afternoon, said Pittsburgh Police Acting Chief Regina McDonald. None of those in custody have been charged.

Nick Lorusso, 52, a truck driver, said he was in his backyard chopping wood about two blocks from the school when he heard seven or eight quick gunshots.

"It was quick, like boom, boom, boom, boom, boom, boom boom, all in a row," he said.

Freshman Julian Drewery, 15, said he was getting into his father's car around 2:55 p.m. ET (1955 GMT) when he saw a fellow student bleeding and thought at first there had been a fight.

"But then I was like, 'No, that can't be from a fight - that's a lot of blood,'" Drewery said. "I saw a kid with blood dripping down his neck ... kids started running."

Brashear High School is the city's largest high school by enrollment with 1,416 students, according to the Pittsburgh Public School district.

(Additional reporting by Barbara Goldberg and Ellen Wulfhorst; Writing by Chris Francescani; Editing by Daniel Trotta, Scott Malone, Alden Bentley and Bob Burgdorfer)