The Netherlands has made it compulsory to wear a face mask in indoor public spaces in an effort to curb to spread of the COVID-19.
The country is one of the last in Europe to introduce such a measure.
The rule will apply to those over the age of 13 in public buildings such as shops, town halls, stations, airports, covered car parks and petrol stations; theaters and concert halls, while people are walking or standing. They can take off their face mask as soon as they have taken their seat.
The Netherlands has been one of the countries worst affected by the second wave of the pandemic.
It broke daily case records throughout October, and the number of new confirmed infections in the country of 17 million has remained fairly stable at about 5,000 a day for several weeks.
The new face mask rule will remain in place for at least three months, wearing a face mask is mandatory on public transport. People who do not wear a face mask will be fined up to 95 euro.
But there are questions over how the measure will be enforced. Major retail chains have said they will inform customers about the rule but not refuse entry to those without a face mask.
"This is not something we consider part of our job as shop workers," a spokesman for the Mirage retail group said to BBC.
Separately, under the measure, students and teachers will have to wear a mask when moving around school buildings but not during lessons. Teachers who move around the classroom while talking, however, will have to put on a face covering.
People do not have to wear a face mask in the following situations: when taking part in theater, dance or sport or performing music as a cultural activity, while swimming in a swimming pool (but face masks should be worn in the changing room and by poolside trainers or supervisors), when they are unable to wear a face mask on medical grounds or because of other limitations.