American University announced Tuesday it would move all classes and instruction online for three weeks after their spring break, becoming the first Washington D.C. metro area university to take the precaution as local coronavirus case numbers rise.

Three University System of Maryland institutions, University of Maryland Baltimore and Towson and Salisbury University, also announced that they are canceling classes in the days before spring break as they prepare to move online.

Twenty-one cases of the novel coronavirus — also known as COVID-19 — have been confirmed across D.C., Maryland and Virginia as of Tuesday afternoon, according to the Washington Post. Three of those cases are in Prince George’s County, where the University of Maryland is located.

While Towson is closing classes across all campuses this week in order to prepare for a potential move online after their spring break, Salisbury, UMBC and American University announced they definitively planned to move classes online through at least April 3.

American University students are currently on spring break, and their classes will begin online March 18, according to an email from university President Sylvia Burwell.

On Monday night, the University of Maryland announced it was suspending all university-related international travel altogether, and cautioned the campus community to prepare to move courses online and to take additional health precautions.

“Given the confirmed case in the county, we will continue to consult with state and county health departments to determine the best course of action for our community,” read a campus-wide email from this university.