Police line (illustration)
Police line (illustration)iStock

Police in San Francisco have arrested at least one person after threats to Jewish students at a high school in the Bay Area were posted on social media, JTA reported Tuesday.

Extra security surrounded the Fremont High campus in Sunnyvale, California, when students returned to school after the long holiday weekend, the local NBC affiliate reported.

The threat was also made against students at Homestead High School in Cupertino, San Francisco television station KRON reported. Both schools are in Silicon Valley.

Administrators were contacted by several students and their families about the anonymous threat posted on Instagram. They did not disclose the specific threat, NBC reported.

School officials reportedly did not believe the threat was credible but contacted police.

The Fremont principal called the threat a “religious rant” targeting Jewish students, KRON reported.

The incidents in San Francisco come on the heels of a threat in South Carolina, where a high school in Spartanburg County had extra security measures for the first day of school, after Jewish and Muslim students were threatened on social media.

School opened without incident at the James Byrnes High School and the other 11 schools in the district, according to JTA.

The threats, which appeared on Facebook, warned that the high school would be attacked Tuesday and included pictures of a person in a gas mask and a knife with a swastika on the handle.

There were two incidents of bomb threats causing evacuations of Jewish institutions in the U.S. this past May.

In one incident, the Jewish Community Center of Greater Ann Arbor, Michigan, was evacuated after an unknown person called in a bomb threat.

Ann Arbor police brought bomb-sniffing dogs to the building, but no explosives were found inside the JCC or on its grounds, according to the report. Staff and students were cleared to return to the building after about an hour.

In a separate incident, a Jewish community center in suburban Phoenix was temporarily evacuated after a bomb threat was phoned in.

In the past year, several other JCCs and Jewish institutions have been evacuated following bomb threats, including ones in Ann Arbor, Michigan; Palm Beach Gardens and Maitland, Florida; and Louisville, Kentucky.