UPDATE: Search has shut down. According to NBC Bay Area: "New info indicates gunman was fabricated. Police said the student who made the inital report recanted his story. They would not say if it was a male or female student." Oy.

Cupertino Middle School, Homestead High and West Valley Elementary in Sunnyvale are all on lockdown after an eyewitness allegedly spotted a gunman on one of the campuses. The man was seen on the Cupertino Middle School campus around 10 a.m., according to reports.

No students of faculty are permitted to leave the school as authorities search for the suspect.

Also, the streets surrounding the school complex -- Bernardo Avenue, Helena Drive, Wright Avenue and Homestead Road -- are blocked off.

We'l update as soon as we know more.