An announcement posted Wednesday evening says schools in the Flagstaff Unified School District will be closed Thursday due to a "cyber security issue."

PHOENIX — All public schools in Flagstaff will be closed Thursday due to a "cyber security issue," the district said Wednesday evening on its website and on social media.

"Due to a cyber security issue that is impacted the ability of FUSD schools to operate normally, there will be no school on Thursday, September 5," the Flagstaff Unified School District's Facebook post read.

"FACTS, childcare centers and FUSD preschools have also been canceled."

FACTS, Family And Community Teaming for Students, is a program offered to students who register.

Zachery Fountain, a district spokesman, told 12 News that all schools will be closed because of a ransomware attack that forced the district's internet to be taken down.

Fountain said with the internet not working, it impacted a lot of systems necessary to run the district, including security.

He added that the district is working with a third-party cybersecurity company to remove the ransomware and get the system back up and running.

The district said on its website that information regarding Friday's schedule will be shared on Thursday.