UPDATE: Monta Vista High and Lincoln Elementary are Closed Thursday Due to Police Activity

UPDATE as of 8:45 a.m. Thursday: Graffiti discovered at Lynbrook High School at 1280 Johnson Ave., in San Jose made reference to a bomb on the campus at Monta Vista High School on McClellan Road in Cupertino, officials said.

A call was made to San Jose Police reporting an incidence of vandalism at Lynbrook, who then reported the threat to Santa Clara County Sheriff’s at about 6:39 a.m. Thursday.

The Sheriff’s bomb squad is checking the campus with specialized bomb detection dogs, according to Sheriff’s spokesman Sgt. Jose Cardoza. The sweep is expected to take at least three hours.

Monta Vista is closed for the day and for safety reasons due to its proximity so is Lincoln Elementary School. Though Kennedy Middle School is also nearby, it is not considered at risk and is still open.

Residents in the neighborhood report news helicopters have been flying around the area since about 7:30 a.m.

As a precaution several roads have been blocked in the area, and they include:

Fort Baker at Presideo
Hyannisport at Linda Vista
Byrne at McClellan
Orange at McClellan
Imperial at McClellan

Police have blocked the intersection of Bubb and McClellan Roads due to police activity at Monta Vista High School. Both Monta Vista High and Lincoln Elementary Schools are closed for the day, officials confirmed. Kennedy Middle School is still open, a school district spokesman said.

“Because of the activity at Monta Vista we were advised to close Lincoln, but Kennedy is still open,” said Jeremy Nishihara, spokesman for Cupertino Union School District.

“(There are) news helicopters right over (the) normally quiet neighborhood,” reports Pam Marino, resident and Patch reporter.

Details of the police activity have not been confirmed Cupertino Patch is working to gather information and will provide updates as they are available.

NBC News reported possible bomb threat.