FAIRFAX, Va. (AP) — Virginia’s largest school system has been hacked and the attackers are seeking a ransom payment to keep them from disclosing stolen personal information.

WRC-TV in Washington reports that the internet hacking group Maze posted some of the data stolen from Fairfax County Public Schools, including student disciplinary records and grades, to prove its hack was successful.

The school system confirmed the hack and said it is investigating and working with law enforcement.

Tina Williams, president of the Fairfax County Federation of Teachers, said in a statement that she was shocked by the hack and that it is “deeply alarming for our community.”

Unrelated, the school system reported that it experienced technical difficulties Friday as students completed the first week of online schooling. The school system blamed the problems on internet provider Verizon, but Verizon said it did not experience any service outages.

The school system said on Twitter that there “will undoubtedly be bumps in the road throughout the distance learning period, but it’s important that students, staff, and families continue to work together as we work through challenges as a team.”