INGHAM COUNTY, Mich.—The Ingham County Health Department over the weekend recommended that all local Michigan State University students in East Lansing self-quarantine.

The recommendation comes as 342 people affiliated with the university have tested positive for COVID-19 since August 24, according to the health department.

To contain the outbreak, the health department is asking students to self-quarantine until Saturday, September 26 at 11:59 p.m.

While not an emergency order, the health department said that “more stringent and mandatory restrictions will be imposed if students do not comply.”

“This is an urgent situation,” said Ingham County Health Officer Linda S. Vail. “The exponential growth of COVID-19 cases must stop. I am concerned about the health and safety of the MSU community, and importantly, I am seriously concerned that unchecked transmission locally will affect the health and safety of all Ingham County residents. If we do not slow the spread immediately, we will be dealing with the consequences across the county for months to come.”

Students should only leave home for essential activities, the health department said.

The health department said that at least a third of new cases recently attended parties or social gatherings, and at least one third of those gatherings are associated with a fraternity or sorority.