Administrators at CalArts closed down the Valencia campus Friday evening in efforts to contain the spread of an illness that affected at least 16 people since Tuesday.

“We are taking all possible health precautions at this point,” CalArts Media Relations Manager Margarete Crane said.

The illness has continued to spread, she said.

CalArts administrators have cancelled all classes and campus activities through the end of day Monday. That includes the popular CalArts Halloween party, which was scheduled for Friday night.

An online health update posted Friday on the university’s website states: “This is not a decision the administration and Student Council made lightly — but the health and safety of the entire CalArts community is our top priority.”

Crane expected that as of Friday evening, the campus should be ready to reopen Tuesday morning.

Students who live on campus are being allowed to remain on campus over the weekend.

Officials from the Los Angeles County Department of Public Health said Thursday they are investigating 16 cases of what they suspect is norovirus.

The highly contagious gastrointestinal virus causes inflammation in the stomach or intestines, leading to stomach pain, nausea, diarrhea and vomiting.

Public health officials could not be reached Friday night to confirm whether the illness has spread.

CalArts faculty, staff members and students are being asked by the Public Health Department to complete an online survey to help pinpoint the cause of the outbreak.

School officials say to check the Campus Health Advisory webpage for up-to-date information.