(CNN) A cluster of Covid-19 cases has been linked to a fraternity party at the University of New Hampshire, health officials say.
The state Department of Health and Human Services said Sunday that it is investigating a potential outbreak tied to a Theta Chi event last weekend.
University officials said more than 100 people, including students, attended the August 29 party and few wore masks.
Eleven people connected to the party have tested positive for the virus, according to university officials.
"Let me be clear: this is reckless behavior and the kind of behavior that undermines our planning and will lead to us switching to a fully remote mode," UNH President James W. Dean Jr. said in a statement.
This is the latest cluster at campuses across the nation, many linked to fraternity parties.
It's a challenge for colleges and universities, since preventing large parties has proven difficult.
The University of North Carolina-Chapel Hill and the University of Notre Dame have had to transition to virtual classes, at least for a time, after cases cropped up days into the semester.
New York University and Northeastern University have suspended students found to have participated in gatherings that violate safety protocols.
Earlier in the summer, clusters of Covid-19 cases the University of Washington, University of California, Berkeley and the University of Mississippi were linked to fraternity parties.
UNH said it would pursue student conduct charges against the organizers and people who went to the party, and that the Theta Chi fraternity has been suspended.
Still, the university's president said in a message to the campus community that the "overwhelming majority" of students were abiding by safety measures.
New Hampshire reported 7,447 Covid-19 cases as of Sunday. About 91% have recovered, while 248 cases are active.
CORRECTION: An earlier version of this article misstated the action taken by Notre Dame when Covid-19 cases spiked after the start of school. Notre Dame transitioned to virtual classes, but the students remained on campus. They have since transitioned back to in-person classes.