The San Francisco State University campus was locked down early Tuesday morning and remained closed for the day due to an investigation of an anonymous threat of armed violence posted to social media, according to a university spokesperson.
A person of interest who police believe is responsible for the threat has been detained, according to the university's police department.
Police said the investigation into the threat is ongoing, but added "we do not believe there are any ongoing threats to the SF State campus or our community."
In-person classes and campus activities were canceled, and students living on campus were advised to shelter in place as university police investigated the threat.
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"Overnight, San Francisco State University Police became aware of a non-specific threat of armed violence on campus which was posted to social media and subsequently deleted. The post was viewed and shared among students and other members of the campus community," a university spokesperson said.
The university added that there's an increased public safety presence on the campus as a measure of caution.
Earlier statements and messages from the university and campus police indicated a "nonspecific threat." The following updated alert was posted on the university's Facebook page at about 8:15 a.m. Tuesday:
"SF State Police are continuing their investigation of an anonymous, non-specific threat. All in-person instruction and services for Tuesday, Sept. 28 should move to remote modalities if possible. Remote instruction and work should continue as planned.
"University buildings, including the library, will remain closed. Residential students are asked to remain in campus residences until notified otherwise. The public safety presence on campus has been increased as part of the ongoing investigation.
Updates will be provided as more information becomes available. Today’s Open Forum with Chancellor Castro will be live streamed."
Earlier Tuesday morning, the following message was sent to university students and employees:
"Due to an ongoing investigation by San Francisco State University Police of an anonymous, non-specific threat, the start of in-person courses and activities on campus are delayed until 10 a.m. on Tuesday, September 28.
"Remote instruction and work should continue as planned. Non-emergency personnel should not report to in-person work until 10 a.m. Residential students should remain in campus residences while the investigation is ongoing. Further updates will be provided by 8 a.m."