In light of the threat made to a school board member in Los Angeles on Tuesday, at least one school district in the Bay Area decided to step up security.
San Francisco Officer Grace Gatpandan said there will be an increased presence at the schools in the city, and school resource officers will be "visibly present" on their assigned campuses.
She said patrol officers will be swinging by the schools and that police have instructed anyone in the district to report any "suspicious activities to police with an expedited response to calls at schools. There are 56,000 students who attend San Francisco Unified School District.
No threats were made against any Bay Area school district. Police in Oakland and San Jose had no plans to make any changes to patrols, officials said.
The extra caution comes just after all Los Angeles Unified School District schools were shuttered and all students at school were sent home for the day.
Supt. Ramon Cortines said the closure in the nation's second-largest school district was out of "an abundance of caution" after the LAUSD received what authorities described as an electronic threat.
Law enforcement sources told the NBC4 I-Team that the email threat was received at 10:15 p.m. PT Monday. The message's last known IP address was in Germany, law enforcement sources said and a district spokesman confirmed.
NBC News reported at least one member of the school board received the emailed bomb threat.
Officials in New York City said schools there received the same anonymous threatbut deemed it "not credible" and were investigating the email as a hoax.
New York Mayor Bill De Blasio and Police Commissioner Bill Bratton said several other districts nationwide also received an email threat, but investigators determined students weren't in any real danger.
NBC Los Angeles' Jonathan Lloyd and NBC News' Andrew Blankstein contriubted to this report.