BRUSSELS — Nonessential shops in Belgium were reopening Tuesday in the wake of encouraging figures about declining daily coronavirus infection rates and hospital admissions.

The government is fearful, however, that the change might lead to massive gatherings in the nation’s most popular shopping centers and streets. Over the weekend, pre-Christmas light festivals already led to crowded scenes in several cities, prompting warnings from virologists about the dangers of reopening too soon.

Belgium, host to the headquarters of the 27-nation European Union, has been one of the hardest-hit countries in Europe during the pandemic. Belgium has reported more than 16,500 deaths linked to the virus during two surges in the spring and the fall.

Under the new rules, shopping has to be done alone or with a minor or a dependant person. Time in a shop is limited to half an hour. Restaurants and bars remain closed.