Belfast Metropolitan College has closed part of its Titanic Quarter campus for a deep clean after a staff member tested positive for Covid-19.
Students at all campuses have been told not to come in for the rest of the week but facilities are expected to reopen on Monday.
The college said in a statement: "We have been notified of one confirmed case of Covid-19 amongst our staff.
"We have followed all required Public Health Agency processes. This has included informing anyone who has been in direct contact with the individual and closing off an area in our Titanic Quarter campus for deep clean."
All sites will be closed to students on Wednesday.
The statement continued: "Belfast Met has notified students not to attend college for the remainder of this week. All sites will be closed to students from Wednesday, 18 March to Friday, 20 March inclusive.
"This will allow staff more time to continue preparing for the delivery of teaching via digital channels.
"At this stage, the college expects to reopen on Monday, March 23."
Meanwhile, all face-to-face classes at Queen's University have ceased.
"All forms of teaching and associated material will now be made available to students online as far as possible," the Belfast university said. "It is recognised that many students may now decide to return home and the university assures students that they will suffer no academic disadvantage as a result."
Ulster University has closed all campuses to teaching and social activities, and staff have been encouraged to work from home if possible.
It said: "The university-wide focus will now be exclusively on teaching through digital channels and extensive preparations have already been made in this regard."