According to an alert sent to media by the San Francisco Police Department, San Francisco's Jose Ortega Elementary School was evacuated on Monday morning for over two hours, as police searched for a bomb but found nothing.

SFPD spokesperson Officer Gordon Shyy says that at about 8 a.m. today, police got a call from the school, which serves grades K-5 and is is located at 400 Sergeant Street in the OMI (Ocean View, Merced Heights, Ingleside) neighborhood.

According to Shyy, school officials believed that they had received a "possible threat." NBC Bay Area, reported that the school district sent an email to parents saying that "a note with a bomb threat was found."

As of 8:45 a.m., the school "is in the process of being evacuated," Shyy said, and "specialized units are being dispatched to the scene." According to KRON4, that includes bomb-sniffing dogs, which are searching for a possible explosive device.

Students will be allowed to return to school after police give the "all-clear," NBC Bay Area reported, but noted that "police on the scene said the threat did not seem credible."

According to SFPD spokesperson Officer Albie Esparza, "After an exterior and interior search of the school it was given the all clear at 10:26 a.m., and children were allowed to return to class at 11:05 a.m.".