Portland, Ore. — A suspect in a shooting that wounded three students outside an alternative high school was arrested early Saturday in what appears to be a gang-related attack, Portland police said.

Witnesses told authorities there may have been a dispute Friday outside Rosemary Anderson High School just before the shooting occurred at a street corner. The victims are students or in affiliated job training programs.

The assailant and two other people fled, and the injured trio went to the school for help, police said. A 16-year-old girl was critically wounded, and a 17-year-old boy and 20-year-old man were hospitalized in fair condition. Another girl was grazed by a bullet.

A student, Oliviann Danley, 16, told The Oregonian she saw a boy run into the school and yell, “Oh my God, did I just get shot?”

Hours later, authorities said they stopped the suspect’s vehicle around 1:30 a.m. and arrested a 22-year-old man. A handgun was found in the vehicle.

Police searched an apartment soon after that is about five blocks east of the shooting. Detectives said they would release the suspect’s name and charges after he is booked into jail.

Gang investigators “feel comfortable saying this is a gang-related shooting based on some of the people involved,” Sgt. Pete Simpson said. Police believe the shooter has gang ties.

Simpson said police were still gathering details on the reported dispute outside the 190-student school that serves at-risk students who were expelled or dropped out or are homeless or single parents.

Police identified the hospitalized victims as Taylor Michelle Zimmers, 16, who was in critical condition; David Jackson-Liday, 20; and Labraye Franklin, 17.

Olyvia Batson, 17, was treated at the scene after a bullet grazed her foot.

Sierra Smith, a 17-year-old student, told The Oregonian she saw one of the male victims getting help from a teacher inside the school.

“He was laying on the ground. He had blood coming out of his stomach,” she said. “It was scary.”

Gang violence in Portland isn’t a new. Some of the violence occurs between rival gangs, but bystanders have also been hurt.

“We’ve made a lot of progress in addressing the gang problem, but we haven’t eradicated it,” Mayor Charlie Hales said Friday. “Today’s really a sad reminder that it’s still with us.”

Portland police have said they saw a spike in gang crime over the summer and have complained they don’t have adequate resources to address the problem. A man died in a drive-by shooting in June and another man was killed in a separate shooting. A 5-year-old boy also was shot in the leg while playing at an apartment complex.

A Multnomah County report on gang activity released in June said crime in the county that includes Portland actually decreased from 2005 to 2012. As inner-city Portland gentrifies, the report said, criminal activity is shifting from northern neighborhoods to areas farther east, including the city of Gresham.

The north Portland neighborhood where the most recent shooting occurred exemplifies the trend. Before Friday, the place once known for gangs had not had a shooting with injuries in nearly four years.

“It brings up a lot of old wounds,” Simpson said.

Dani Gonzales, 64, has lived in the neighborhood for 25 years and said it’s generally safe but there has always been some gang activity.

“Kids just get silly and get crazy ideas. I don’t know what goes on in their heads,” Gonzales said.

There was another school shooting in the Portland area in June, but it was not gang-related. A freshman killed another boy in a locker room, and a bullet grazed a teacher before the shooter went into a bathroom and died from a self-inflicted gunshot, police said.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.