A "Covid Safe Ticket Plus" rule, combining the CST with mandatory mask wearing, is now applied indoors for anyone above the age of 10 years.
The authorities, who are expected to meet again in January, have asked people to respect the 1.5-metre social distancing indoors, and limit social contacts outdoors, though no "bubbles" will be imposed for now, Xinhua news agency reported.
Nightclubs, public and private events of more than 50 people indoors and 100 outdoors will also require the use of a CST and a mask.
Teleworking is compulsory four days a week until December 13, and then three days a week, and no more than 20 per cent of all staff who are required to work from home can be in the office at one time.
Covid-19 indicators in Belgium have been rising steadily for weeks and hospitals were overburdened by staff shortages and a rise in hospital admissions.
Between November 13 and 19, there were an average of 268.3 hospital admissions per day, an increase of 29 per cent compared to the previous reference period, according to the Sciensano Public Health Institute.
In total, 2,957 people are currently hospitalized due to Covid-19, including 603 patients in intensive care.
On Monday, a total of 20,768 Covid-19 cases were recorded across the country, the highest since the end of October 2020, at the height of the second wave.