All classes at the National University of Singapore's (NUS) School of Design and Environment (SDE) will be conducted online from today, after one of its professors became ill with the new coronavirus.

NUS president Tan Eng Chye said last night that as an additional precaution, in-person classes, tests, meetings or interactions between SDE students and staff, as well as small-group studio sessions, will be suspended until next Friday. The university's recess week then kicks in from Feb 22 to March 1.

The SDE has over 1,900 undergraduates who study architecture, industrial design, real estate or project and facilities management. It also has about 600 graduate students.

The Singaporean professor had attended the Grace Assembly of God church, which has emerged as the fifth cluster of coronavirus infection here. He developed symptoms on Monday night and did not return to the campus.

An NUS spokesman said the professor's last contact with students had been on Feb 5.

"Staff who were in close contact with the professor were swiftly put on leave of absence and we are providing them with assistance and support," he said, adding that NUS has also stepped up its cleaning efforts and precautionary measures.

Professor Tan said in a circular that the areas the professor had used or visited in the SDE on Monday have been thoroughly disinfected, including "all high-traffic areas such as hand railings, lifts and lift lobbies around the affected premises".

He added: "We have immediately ramped up the frequency of cleaning at SDE. We have also increased the cleaning frequency of restrooms in SDE from twice a day to four times a day."

NUS implemented e-learning for all classes with over 50 students across all faculties on Monday. All events and activities with over 50 participants have been cancelled or deferred. Instructors are also required to take pictures of each face-to-face class they teach and keep them for two weeks to facilitate contact tracing if needed.

All staff and students must take their temperatures twice a day and declare them in an online system.

Prof Tan said: "We are doing everything we can to keep everyone on our campuses safe and healthy."

In an update yesterday evening, NUS dean of students Leong Ching acknowledged that students may be anxious, but reassured them that the university is doing all it can to keep them safe.

The impact of the professor's case is "localised and limited", she said, as he last attended a meeting on Monday at SDE before going home in the afternoon. "In short, he was last on campus when he was well and had no symptoms."

"NUS' response measures are swift and already exceed those required by the Ministry of Health," she added. In response to an online petition calling for official permission to allow foreign students to leave Singapore, she noted that any international student who wants to return home can apply for a leave of absence.

Associate Professor Leong added that she has also been keeping student leaders updated daily on the ongoing situation, including cases of students on leave of absence on campus, who need to be taken to hospital via ambulance. So far, they are found to have "minor conditions not virus-related", or are "discharged and well", she said.