SAN FRANCISCO, May 11 (Xinhua) -- A student of a high school northeast of San Francisco has been arrested for hacking into the computer system of the Mount Diablo Unified School District in order to change the grades of his own and other students, a TV report said on Friday.

The student whose name was not disclosed because of being a juvenile, was studying at Ygnacio Valley High School in Concord, a city northeast of San Francisco in northern California.

He was accused of targeting teachers with a phishing scam and hacking into the Mount Diablo Unified School District computer system, in an attempt to change his grades as well as those of other students, police said.

"We wrote numerous search warrants to get the IP addresses of the possible phishing site email ... we did good old fashioned police detective work and we narrowed it down to an address," said Sgt. Carl Cruz, the Concord Police Financial Crimes Supervisor.

Police said the high school student had created a fake website and emailed teachers in a phishing attempt to get their log-in and personal information.

One teacher actually logged into the fake website, which made it possible for the student to access the Mount Diablo Unified School District IT network and get into the grade system, according to the police.

Police said the student successfully changed the grades of his own and a dozen others.

A Mount Diablo Unified School District spokeswoman said the student has been suspended.