Three western Massachusetts colleges are extending their mask mandates and a fourth could be doing the same.

Mount Holyoke College, Smith College and Hampshire College will be extending mask mandates indefinitely.

In an open letter to students, Mount Holyoke president Lynn Pasquerella cited the relatively high confirmed COVID-19 case count on campus. The school was set to drop the requirement last week.

Nearby Amherst College will be conducting anonymous surveys in classes and labs, and the results will determine what the school does. If anyone in a class wants to continue masking up, then masks will be required for the entire class.