An unknown number of high school students in the San Francisco Unified School District are staging a walkout today in protest of the violence in the Middle East, and saying they demand a ceasefire.

The walkout was organized by the Arab Resource & Organizing Center (AROC), which put out the notice below on social media, also announcing a 10 a.m. press conference on the steps of San Francisco City Hall.

The text of the walkout notice focuses on Israel's attacks in Gaza, and blames an Israeli airstrike for the killing of "at least 500 people" at a hospital in Gaza Tuesday — something that Israeli intelligence has blamed on a misfired rocket by the Hamas-affiliated group Palestinian Islamic Jihad. U.S. intelligence has said, based on preliminary findings, that it supports Israel's intelligence, and in a speech President Biden on Wednesday blamed the explosion on "the other side."

The walkout is being called on a national level, but so far appears to be centered in San Francisco.

AROC tells the Chronicle that students from Lincoln, John O’Connell, Galileo, Balboa, Lowell, Washington, and June Jordan high schools are expected to participate in the walkout, along with students from City College of San Francisco.

The Jewish News of Northern California refers to AROC as "a San Francisco-based activist group known for its strident criticism of Israel," and they report, "The planned walkout has raised concerns among Bay Area Jews who fear the event will make Jewish and pro-Israel students feel isolated and vulnerable."

A group of 70 parents of public school students in SF signed an open letter to SFUSD Superintendent Matt Wayne on Tuesday, expressing concern about the walkout. And as one parent, Amanda Kahn Fried, tells the Jewish News, "Walkouts like this disrupt any opportunity for adults to help students navigate this." And, Kahn Fried adds, students with differing sympathies need help to be able to discuss these issues. "They’re sitting in the same class. And these are issues adults haven’t been able to solve," Kahn Fried says.

AROC has published a set of talking points for students to use if they end up speaking to the media. These include student demands such as, "We stand against the brutal bombardment of besieged Gaza, to demand an immediate ceasefire, and to break the silence on Palestine at our schools."

"Safety remains our top priority," says Superintendent Matt Wayne in a statement.

The SFUSD has said that students who participate will be marked absent.

"The youth of Gaza deserve to live full lives and to live in freedom and dignity,” says Lowell High student Helena Awwad, in a statement, per the Chronicle. "We plan to raise our voices to call for an end to our government’s complicity in Israel’s crimes, for the freedom of all people, and so we call on students around the nation to join us this Wednesday."

As of 10:55 a.m., NBC Bay Area reporter Marianne Favro said that 140 Lowell High School students were participating in the protest.