Four Jersey City high school students have been charged after authorities say they accessed the public school district’s computer system and changed grades for some students, The Jersey Journal has learned.

According to a source in the school district, board of education members were notified by email Friday afternoon that four Dickinson High School students had been arrested earlier in the day. Jersey City school officials and a spokeswoman for the police department did not return requests for more information.

The email said school officials “do not believe any personal information was accessed.”

It was not immediately known what the students were charged with, but if they are not yet 18, their cases would be heard in family court.

The students are accused of using the usernames and passwords of staff members, the email said. It was not clear how many staff members were hacked.

School officials said in the email that student grades were changed, but “not necessarily their own.” Teachers saw that some grades had been changed, corrected them and reported the incidents, the email said.

The police department and district officials traced what the students had done inside the system and identified the students involved, the email said.

Jersey Journal Staff Writer Terrence T. McDonald contributed to this report.