Huntsville City Schools says it is closing all schools and campuses for the remainder of the day Monday “due to a potential cybersecurity threat.”

The school system said “students, families, and faculty and staff members should shut down their district-issued devices and ensure the devices remain off until further notice.”

The system also says no one should log in to any HCS platforms from either school or home.

Craig Williams, school system spokesperson, said it appears to be a ransomware attack and that the system is working with local and federal authorities.

Williams said they found about the threat because the school district's IT help desk received a high volume of calls, more than normal for a Monday.

He said it is not known if anyone's information has been compromised, and that it is not yet known if school will be in session on Tuesday.

All after-school activities and athletics events will continue as planned.