A mother and daughter were arrested after brawling broke out at an anger management assembly in a school in the United States.
Sharod Bailey, 33, was charged with trespassing and disorderly conduct after she stormed into Woodlawn high school, Baltimore, this month.
She accused pupils of bullying her 15-year-old daughter, Tearra High.
Fighting then erupted among the 750 14 to 15-year-old pupils who had been learning about peaceful ways of resolving conflicts.
Tearra was charged with second-degree assault and 11 students were suspended.
Charles Herndon, Baltimore county public schools spokesman, said: "A parent came into school to play a role in resolving conflict between her daughter and some other students and got into a verbal conflagration then a little bit of a scuffle."
C Anthony Thompson, the principal, said the scene was chaos as appeals for calm from the anger management specialist were ignored.
Mr Herndon said: "He did try to deploy anger management techniques, but I don't know how effective they were."
After 15 minutes order was restored and the teenagers were taken back to their classes.
Mr Herndon added that Woodlawn had been trying to rehabilitate its image after a fashion show dissolved into chaos last year. He said: "Several people from the community began disrupting the show and picking fights with students. Neighbourhood conflicts tend to bleed into school."
Despite the two incidents, Mr Herndon insisted it had been a quiet year.
Between August 2002 and February 2003 police were called to the school 26 times.
Mr Herndon said: "There are different ways of looking at this. Parents might point to the fact that there were more calls to the police, but this indicates lower tolerance for misbehaviour."
Woodlawn high's website greets visitors with the slogan "Welcome to the Warriors' Domain."
Michael Fisher, the director of the British Association of Anger Management said: "This does not surprise me. When we first started four-and-a-half years ago in a north London school the kids used to off-load. They would tear the class apart. Behaviour did improve in lessons, but that was because they had taken out in their time with us. We do one-on- one work first before putting them in groups, and it is better now."