School administrators and teachers' union officials say there has been another student assault on a teacher at New Bedford High School.
Authorities said a female student threw a metal trash can that struck a teacher in the head earlier this week. The teacher went to the school nurse's office but did not require hospitalization.
An 18-year-old male student was expelled and criminally charged last month for throwing a chair at a teacher who had confiscated his cellphone.
Superintendent Pia Durkin did not say what prompted the latest incident, but credited the teacher for trying to de-escalate the situation. The student "is being removed" from the school.
Teachers' union president Louis St. John said an emergency union meeting has been scheduled to discuss several issues, including student violence "without adequate recrimination."