NEW ROCHELLE, N.Y. (CBSNewYork) — A 16-year-old boy was stabbed at New Rochelle High School in the third violent incident involving students from the school in a week.

As CBS2’s Tony Aiello reported, the school for years has been the pride of New Rochelle. With 3,400 students, it is the biggest in Westchester County — equipped with an art museum and a planetarium.

READ MORE: 16-Year-Old Isaiah Levine Killed In Double Shooting On Lower East Side, Second Victim In Hospital

But now, there has been a spate of violence. Parents are demanding change after a 16-year-old was stabbed – suffering injuries to his lung and spleen.

New Rochelle police said a 15-year-old student stabbed his schoolmate in a second floor classroom inside the school around 8:50 a.m. Thursday. The assailant fled the scene, police said.

Sources tell CBS2’s Tony Aiello that the alleged attacker was himself attacked Wednesday at a pizzeria a block from campus. The motive for Thursday’s stabbing appears to be revenge.

The suspect was seen on video leaving the building shortly after the incident, New Rochelle police said.

“It’s very scary,” said Pam Devita. “They’re all shaken up, and, I mean, this shouldn’t be happening.”

The violence prompted Devita to take her son, Michael, out of school early.

“I just feel weird because it never really happened before,” said Michael Devita. “Like, it’s new to me, at least, of how, like, the situations are like progressing.”

At a school board meeting Thursday night, parents were incredibly impassioned – angry and afraid of what was next after the violent incident.

“It was a nightmare today,” parent Yolanda Valencia told CBS2’s Jessica Layton. “I didn’t have answers.”

“You should not have other children that want to learn have to be concerned — are they going to get stabbed; going to get shot?” said parent Cathy Caliendo.

Caliendo was among many moms contemplating sending her child back to the school after the stabbing.

Parents were first alerted to the stabbing by text and an automated phone message announcing, “There is currently a lockout in effect at NRHS.”

READ MORE: Tony Award-Winning Temptations Musical 'Ain't Too Proud' Reopens On Broadway

Several dozen parents rushed to the school after receiving a text alert and automated phone message notifying them of a “lockout” on campus.

They are now talking about a show of force at the New Rochelle Board of Education meeting on Jan. 30 to demand a plan to address security concerns at the high school.

“My daughter is in ninth grade here at New Rochelle High and she said that they heard a scream and then they heard the teacher screaming,” parent Helen Pappas said. “I want to take my daughter out, I want to home school her. It’s insane, I just don’t feel comfortable sending her to school.”

“It’s not good, they should at this point maybe put a metal detectors given what’s been going on the last ten days or so,” parents Bruce Kuligowski said.

“It’s just very upsetting and confusing to all of us. We love New Rochelle and we support everyone and just want to make sure the kids are safe,” parent Erica Christ said. “The option is to stay and never leave and fight through it and figure it all out as a community. It’s the only option we have.”

Parent Nancy Murano wants to see action.

“What’s the plan? What are you doing tomorrow morning so that I know when I drop off my daughter she’s going to be OK?” Murano said.

Parents said the district must act, and the community pull together.

“We remain entirely confident of our community’s positive, safe and bright future, and determined individually and collectively, do our parts to restore the trust and peace of mind that all parents and residents of New Rochelle deserve,” said New Rochelle Mayor Noam Bramson.

The 16-year-old was taken to a local hospital where he is being treated for two puncture wounds to his left torso. The injuries do not appear to be life threatening.

The incident comes a week after a New Rochelle High School student, 16-year-old Valaree Megan Schwab, was stabbed to death at a Dunkin’ Donuts. Her classmate has been charged with second-degree murder.

At the Thursday night meeting, school board members were in the hot seat, with parents demanding to know what they plan to do to protect their kids. Along with promising uniformed police officers inside and outside school, district officials admit they’re just as concerned.

“Safety and security of the students and staff is paramount,” said School Board President Rachel Relkin. “Like many of you, we have many questions about recent events that must be answered.”

MORE NEWS: DEP Says New York City Tap Water Might Smell, Taste Different Because Of Different Supply Systems

The city and the school board jointly announced stepped up security inside the school, more patrols outside, and additional patrols in the North Avenue business district where students often hang out.