Minneapolis Public Schools urged families on Wednesday to change passwords, watch for fraudulent emails and monitor their financial accounts in the wake of a cyberattack on the district.

The district's network was infected with an encryption virus, and "an unauthorized threat actor may have been able to access certain data located within the MPS environment," according to the latest emailed update sent to families.

"Please note, MPS has not paid a ransom to the threat actors and the investigation has not found any evidence that any data accessed has been used to commit fraud," read the email.

District officials said the process of restoring systems from "secure backups" was largely complete. Still, teachers continued to report ongoing computer issues on Wednesday, said Greta Callahan, teacher chapter president of the Minneapolis Federation of Teachers.

"We thank you all for your patience and understanding," read the email to families. "MPS continues working toward full restoration of our systems. By working together, we can help protect ourselves and our organization from any future attacks."