However, a majority 569 have already recovered and 442 people are under active treatment.
Nine people have died of the virus so far while over half of the total infections are from navy personnel only.
The 28 tested positive on Tuesday are identified as navy men who are undergoing quarantine.
Over 80 percent of the infections reported in past four weeks are from navy while the majority of rest are from quarantine centers with hardly any community cases reported. This has encouraged Sri Lankan government to relax curfew in majority of districts with economic and commercial activities slowly returning to normalcy.