A 13-year-old student faces expulsion from a St. Paul junior high school after she allegedly stabbed a classmate Wednesday in a hallway.

The girl allegedly cut the boy, 13, in the chest and arm with a small knife at about 12:30 p.m., sending him to Regions Hospital. Officials at Highland Park Junior High School said his injuries were not serious. By the end of the school day, he had already been released or was about to be released from the hospital, they said.

Both students are seventh-graders.

The incident happened as students were changing classes. Other than the commotion surrounding the altercation, the school day was otherwise not disrupted, said school district spokesman Brett Johnson.

Authorities wouldn't name either student, but the girl was taken into custody and is detained at the Ramsey County Juvenile Detention Center, said St. Paul police spokesman Peter Crum. He would not say what type of knife was used in the alleged assault, citing the current investigation.

Charlene Hoff, the school's principal, said the minimum disciplinary action for an incident such as this one is a 10-day suspension and a mandatory referral to the St. Paul Public School District for expulsion.

Hoff said the boy received "a small puncture wound to his chest and arm."

She described the stabbing as an isolated incident between two people. "It's a conflict we'd been dealing with and that we thought was resolved," she said. Counselors and administrators had been involved in the previous conflict, she said, which was a verbal one. She added that she did not know of any specific threats made.

A third student who tried to intervene during the altercation was cut on the finger, but the injury was minor, said Howie Padilla, a spokesman for the district. He added that the boy and girl had some sort of relationship.

Hoff said she couldn't confirm reports that the students were in a romantic relationship. At that age, she said, children can be boyfriend and girlfriend for five minutes.

Two junior high boys standing outside the school at the end of the day said that the incident happened on the first-floor of the school at the bottom of a staircase.

"It's scary," one of the boys said. "This doesn't happen a lot."

The boys, who did not want to give their names, said they had been kept in class until police could react.

The school, at 975 Snelling Av. S., doesn't have metal detectors. The school hasn't had other serious incidents in the recent past, Hoff said.

In a letter sent to parents Wednesday, she said that the student's injuries weren't serious.

"Staff members acted quickly to control the situation and school administration confiscated the weapon," she wrote.

The letter also said the district has several plans in place to protect students and staff, which include creating a welcoming environment for students, and ongoing training for staff in safety training, non-violent crisis intervention, emergency response and threat assessment.

Staff writer Pat Pheifer contributed to this report. Allie Shah • 651-298-1550 Emily Johns • 651-298-1541