Update 12:42 p.m. Investigation into email continues
An investigation as to who sent an email Tuesday that threatened Fountain Valley High School with explosives and a shooting Wednesday is ongoing, Fountain Valley Police Sergeant Tony Luce told KPCC.
Luce said the email said a student "had planted explosives on the school campus and would be coming to school with an assault rifle to kill any people on campus that survived the explosion."
After a search of the campus, authorities found no explosives or weapons of any kind.
The email was traced to the account of a 17-year-old FVHS student, who denied he sent it.
"He cooperated with officers and let them go through his computer and cell phone and in a preliminary search of his phone and computer they weren’t able to find any evidence it came from him," said Luce.
A computer forensic technician will be looking more in depth to try to find out where the email originated.
-- KPCC's Bianca Ramirez and Jessica Hamlin
Update 11:14 a.m. Threat is a hoax, police say
After searching the campus, police have determined the emailed bomb and shooting threat for Fountain Valley High School Wednesday to be a hoax, Fountain Valley Police Sergeant Tony Luce told NBC-LA.
Administrators and teachers have been let back on campus but school for students remains canceled for the rest of the day.
Police found no evidence of a threat at the school or evidence that the 17-year-old whose email address sent the threat actually sent the email, said Luce, according to the station.
Police determined the email threat was not sent from the 17-year-old's cell phone or computer, NBC-LA reported. The student was questioned but not taken into custody and is not being identified at this time since it is a possibility his account was hacked.
Wednesday afternoon activities such as sports practices will resume as scheduled, FVHS principal Chris Herzfeld said in a message on the high school's website.
Classes will resume on a regular bell schedule Thursday, Herzfeld noted.
Earlier: Bomb threat closes high school
Classes are canceled at an Orange County high school Wednesday as police investigate an emailed bomb threat, the Associated Press reported.
NBC-LA has since learned from authorities that the threat also included a shooting.
Police spokeswoman Daniella Valadez says officials decided to shut down Fountain Valley High after receiving word of the threat early Wednesday, according to AP.
The email, sent to the school at 10 p.m. Tuesday, said there were hidden explosives on campus and that a student would come Wednesday and shoot and kill any surviving students, Fountain Valley Police Department Sergeant Tony Luce told NBC-LA.
After the email was traced to a 17-year-old student, officers searched the student's home but found no evidence on his cell phone or computer that the email came from him, according to Luce. The student also denied sending the threat and there is no indication that he has access to firearms.
Forensic experts will take a second look at the student suspect's computer and cell phone, said Luce.
Police will remain on the scene until the area is safe to reopen. Bushard Street is closed between Slater and Talbert avenues, NBC-LA reported.
The high school earlier shared on twitter that the school was closed until further notice but has since shared on facebook that classes are canceled for the entire day.
This article has been updated.