An 18-year-old student has been charged with repeatedly punching in the face and giving a concussion to the principal of Harrison Education Center, a high school in north Minneapolis for kids with severe behavioral or emotional disorders.

Lashawnte Simone Bright, of Minneapolis, who turned 18 on Wednesday, was charged Tuesday in a juvenile petition with felony third-degree assault and gross-misdemeanor fourth-degree assault of a school official, Hennepin County Attorney Mike Freeman said.

"We can't have situations where principals and staff and teachers are being assaulted," Freeman said during an afternoon news conference. "We cannot accept disrespect and violence."

Revelations of three assaults since last month at Harrison and another in November at River Bend, a K-8 alternative school, prompted the Minneapolis Public Schools to call a news conference last week to reassure the public that officials were doing all they could to ensure a safe atmosphere at the school.

On Jan. 7, the same day district leadership called the news conference, a 14-year-old boy was arrested at Harrison in connection with the assault of a female teacher. A school spokesman said no one was injured.

On Dec. 7, according to the petition, Bright was in the cafeteria when Principal Monica Fabre asked her to leave, because she had been suspended and was barred from the school.

The principal, holding Bright's purse, was escorting her toward the door when the teen grabbed Fabre by the hair, pulled her to the ground and punched her in the face several times, the court document continued. Other staff members pulled Bright off Fabre, and Bright left the scene. Fabre, 47, suffered a concussion and other head injuries from the assault and has yet to return to work.

Harrison's on-site officer located Bright that day near Oak Park and Logan avenues, a few doors from her house, and directed her into his squad car.

Messages left Wednesday with members of Bright's family seeking reaction to the charges were not returned.

The day after Fabre was attacked, an 18-year-old male student was arrested on suspicion of assaulting Sakaria O. Ashirow, 29, a paraprofessional in his first school year at Harrison. Ashirow said he didn't miss work because of the incident.

River Bend special education teacher Jenny Cramer told school board members in December that she was assaulted by a female student on Nov. 10 after "trying to de-escalate" a situation. "The violence that occurs at River Bend would likely shock many members of society," she said.

A spokesman for the county attorney's office said he's unaware of charges being brought in the other cases.

Metro-area schools have been struggling with the issue of violence toward teachers for several months. In St. Paul, after a Central High teacher was choked into unconsciousness by a student on Dec. 4, Superintendent Valeria Silva began instituting corrective measures. On Monday, she reassigned administrators to spend part of their day at sites where fighting-related suspensions have surged and is taking steps to ensure that all staff members supervise students in halls between classes and before and after school.

Staff writer Karen Zamora contributed to this report.