A poster to remind people to stay safe is seen at a bus stop in Brussels, Belgium, April 21, 2020. Belgium reported 973 new cases of COVID-19 infection, raising the cumulative number of confirmed cases from 39,983 to 40,956 by Tuesday morning, according to fresh figures from the public health institute Sciensano. (Xinhua/Zheng Huansong)

A man does exercise at a park in Brussels, Belgium, April 21, 2020. Belgium reported 973 new cases of COVID-19 infection, raising the cumulative number of confirmed cases from 39,983 to 40,956 by Tuesday morning, according to fresh figures from the public health institute Sciensano. (Xinhua/Zheng Huansong)

Signs are put on the seats on a bus to prevent people from sitting close to each other in Brussels, Belgium, April 21, 2020. Belgium reported 973 new cases of COVID-19 infection, raising the cumulative number of confirmed cases from 39,983 to 40,956 by Tuesday morning, according to fresh figures from the public health institute Sciensano. (Xinhua/Zheng Huansong)

A woman rides on the Grand Place in Brussels, Belgium, April 21, 2020. Belgium reported 973 new cases of COVID-19 infection, raising the cumulative number of confirmed cases from 39,983 to 40,956 by Tuesday morning, according to fresh figures from the public health institute Sciensano. (Xinhua/Zheng Huansong)

A woman sits on the bench of a closed restaurant at the Grand Place in Brussels, Belgium, April 21, 2020. Belgium reported 973 new cases of COVID-19 infection, raising the cumulative number of confirmed cases from 39,983 to 40,956 by Tuesday morning, according to fresh figures from the public health institute Sciensano. (Xinhua/Zheng Huansong)