The Los Angeles Unified School District confirmed late Monday that a major system outage that emerged over the weekend was due to a ransomware attack targeting its Information Technology infrastructure.

“Since the identification of the incident, which is likely criminal in nature, we continue to assess the situation with law enforcement agencies,” the district said in a statement.

The district said disruptions included access to email, computer systems, and applications. It did not reveal if the ransom was paid.

The district says students should return to class as usual on Tuesday.

“We are working collaboratively with our partners to address any and all impacted services. While we do not expect major technical issues that will prevent Los Angeles Unified from providing instruction and transportation, food or Beyond the Bell services, business operations may be delayed or modified.”

After reports of IT issues first emerged Sunday, LAUSD superintendent Alberto Carvalho tweeted Monday morning that LAUSD’s “Systems are temporarily disabled due to unforeseen circumstances.” His tweet was in response to a question from user CocoGail, who could not get into the system to post grades for students.

The unified response to the attack has reached the highest levels of government, the district said.

“After the District contacted officials over the holiday weekend, the White House brought together the Department of Education, the Federal Bureau of Investigation (FBI) and the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA) to provide rapid, incident response support to Los Angeles Unified, building on the immediate support by local law enforcement agencies.”

The district said it is calling for an independent task force to make recommendations to prevent future attacks and will make additional investments in human and technical resources.