The Toronto District School Board (TDSB) says it is aware of a third antisemitic incident involving students this month, this time involving a Jewish teacher at a school in North York.

Brian Fong, principal at Pleasant Public School, east of Bathurst Street and Steeles Avenue, told parents in a letter sent home Friday that two students in a classroom did not put their hands down after raising them for a prolonged period, in what the teacher present in the classroom understood to be the Nazi salute.

"Yesterday, during a class discussion, students were asked to raise their hands in response to a question," Fong wrote in the letter. "Two students kept their hands up for a longer period of time, which was seen by the teacher as a 'Nazi salute.'"

In an interview with CTV News Toronto, the teacher involved said she felt so shocked and attacked that she walked out of the room.

"It's really heavy on my heart," said Sarah, who did not want to use her last name. "This is a symbol of hate, and that's how I felt in the moment too."

Fong said Grade 6 students at the school will participate in a session with an educator who speaks about antisemitic and the ongoing and generational legacy of the Holocaust.

"In terms of immediate action, we are in the process of arranging a program with Michelle Glied- Goldstein, a well-known and respected educator from "Carrying Holocaust Testimony" for all our Grade Six students."

It's at least the third incident involving students at the TDSB allegedly displaying hateful antisemitic gestures and symbols this month.

On Feb. 17, a French teacher at Valley Park Middle School who happens to be the child of Holocaust survivors reported she was surrounded by students who allegedly gave her the Nazi salute.

On Feb. 8, the TDSB said a group of students at Charles H. Best Middle School made a swastika out of construction paper without realizing its significance as a hate symbol. Earlier that day, students at the school allegedly surrounded a Jewish student and performed the Nazi salute.

The incident at Valley Park Middle School is being investigated by Toronto police, a spokesperson for the service said Friday.

In a tweet Friday afternoon, interim Toronto Police Chief James Ramer said police are aware of two antisemitic incidents at local schools in 32 Division.

"We've sent officers to learn more & we will work with schools to determine the next steps," Ramer tweeted. "There is no place for hate in Toronto & @TorontoPolice will investigate any & all cases for appropriate charges."

Michael Mostyn, the chief executive officer of B'Nai Brith Canada, told CTV News Toronto that there is a systemic problem with antisemitism within the TDSB.

He said there should also be a larger discussion about why these incidents keep happening in schools and what needs to be done to address them.

"This is extremely disappointing to see, especially with young children. And it really is pointing towards a very disturbing trend," Mostyn said.

"I think that there's a very large lack of Holocaust-related education, but also probably a lack of historical understanding here in Canada."

Mostyn said these incidents should be taken seriously and that the TDSB should deal with them broadly and not just on a case-by-case basis.

"We have a serious problem. Lack of respect, lack of civility, but also a willingness to go up into somebody's face and do the most vile, racist salute that's possible for a Jewish person," he said.

The organization wants to see a plan from the board on how it will deal with antisemitism.

"Education is part of it. Broader Holocaust education is part of it, but a plan on antisemitism directly, which is much broader than Holocaust education," Mostyn said. "And I think it needs to as well go beyond antisemitism, go beyond racism, and deal with respectful behaviour and what's expected of our youth even with respect to teachers."

- with files from CTV News' Beth Macdonell