In the latest acts of violence in the Philadelphia School District, an elementary school principal was knocked to the ground by a female student yesterday and three teachers were assaulted in the last two days.

The most recent attack happened on a day when leaders converged on West Philadelphia High School to talk about solutions to the problems there and an afternoon fire prompted yet another evacuation.

The assault on the principal, which triggered one arrest, happened at Kenderton Elementary, a K-8 school in North Philadelphia, when Robin Wilkins tried to break up a scuffle between a seventh-grade girl and eighth-grade girl.

"The eighth grader ran up from behind and punched the principal in the back and shoulder area, knocking her to the ground," district spokeswoman Felecia Ward said.

Wilkins then saw another eighth grader running toward her. That girl tried to strike her, but Wilkins had used her walkie-talkie to call for help and police officers were able to halt an attack. The girl struck a female school police officer and pulled her hair, and even after she was subdued continued to make "terroristic threats" to Wilkins, Ward said.

"It took a lot of people to get her down to the ground," Ward said.

The eighth-grade student who struck Wilkins was charged with assault.

Ward said the other eighth-grade girl was a special-education student who had not taken her medication.

Under a new district policy, the student who hit Wilkins will be suspended for 10 days and recommended for expulsion to a disciplinary school. The seventh grader, who did not assault a staffer, will likely be recommended for a three-day suspension, Ward said.

The other eighth grader is guided by a separate disciplinary code. Special-education students can be suspended for a cumulative maximum of 15 school days, and any further measures must be cleared by the state.

Edison Schools Inc. general manager Todd McIntire, who was at Kenderton yesterday, described Wilkins as a veteran educator in her second year as principal of Kenderton, which Edison operates. Wilkins had worked as a principal in the Chester-Upland School District before coming to Philadelphia.

McIntire said the attack was an isolated incident.

"Everything has been going very well at Kenderton this year. It's a school that has been performing very well, actually," McIntire said.

He said Wilkins did not require medical assistance.

"She was a little harried because of having to manage the situation and also with the police folks, but she's fine," he said.

Police said that in addition to the Kenderton incident, there were three other assaults on teachers yesterday and Monday.

At Olney High, a 16-year-old female student slammed a teacher's hand in a door after the teacher asked the girl to leave class. At Emlen Elementary in Germantown, a teacher trying to break up a fight was punched twice by a female student. The girl was charged with assault.

On Monday, a 14-year-old student pulled a teacher's arm after the teacher took a bookbag from the student, police said. That student was also charged with assault.

Schools Chief Executive Officer Paul Vallas said the district takes a zero-tolerance approach to assaults on staff.

"If you assault an employee, even if that employee is not hurt, is not scratched, you face expulsion," Vallas said.

There have been 63 assaults this school year on administrators, including principals, assistant principals, deans of students and others. That includes assaults committed by students, parents and other adults, Vallas said. It represents about 12 percent of the total assaults on employees, Vallas said.

"Clearly, kids are getting much more physical and they're becoming much more violent," he said. "It defies reason that anyone would want to hit a teacher or a principal under any circumstances. We definitely live in a different time."

The district was also coping with another fire at embattled West Philadelphia High, where blazes have been set nearly every school day over the last week and seven staffers have been assaulted in two weeks.

This time, a locker fire set just before 1 p.m. yesterday prompted the evacuation of the building. The blaze was quickly extinguished with no injuries.

No arrests were made in connection with the fire, but two students were arrested on disorderly conduct charges.