An unknown male called the school at about 10:45 a.m. and said there was a bomb on campus, police said.
Police and school officials immediately evacuated students to the Diablo Valley College parking lot across the street while a search of the school was conducted, police said.
Nothing suspicious was found on school grounds and police declared the school secure at about 11:30 a.m. and began escorting students back inside, police said.
Police were still investigating the bomb threat this afternoon and were asking that anyone with information about the case call investigators at (925) 288-4633.
