The lockdown at Lae's University of Technology started on Sunday after the deaths of two academics - one the head of the Department of Mechanical Engineering, Dr Gabriel Arpa.
Unitech's administration said the cause of their deaths is yet to be confirmed but both people had Covid-19 symptoms, The National newspaper reported.
Unitech said as an interim precaution, they had decided to suspend all classes for two weeks and impose a total lockdown.
The university, in PNG's second largest city, had also implemented the mandatory wearing of masks by students, staff and dependents while on campus, with no one allowed in public spaces without one.
Strict social distancing and the regular use of hand sanitisers was also being enforced.
Classes disrupted by the lockdown will be incorporated into the second half of the semester according to Unitech administration.
PNG has more than 7000 Covid-19 cases with 67 people having died.