Hong Kong, Dec 7 : A fourth wave of the coronavirus pandemic in Hong Kong due to a number of untraceable confirmed cases was getting worse and could last until 2021, experts said on Monday. On Sunday, the city's overall Covid-19 caseload increased to 6,897 after 95 new infections were reported, while the death toll surged to 112, the South China Morning Post reported. Speaking on a radio show, infectious disease expert Leung Chi-chiu urged the city's residents to avoid going out, saying the outbreak would not otherwise be brought under control no matter what social-distancing measures were in place. "A lot of people are still going out and having gatherings," Leung said, adding that it would be safest for residents to stay at home or else risk community transmission. Also on Monday, Ho Pak-leung, a University of Hong Kong microbiologist, said the city government had not been cautious enough, adding that the fourth wave had been getting worse and it will not be under control before the end of the year. /IANS