Gold fell below the key psychological level of $1,900 on Monday to its lowest in more than a week.
Unease over record new coronavirus cases in Europe, U.S.
Sport and cultural facilities in Brussels must close and residents will face a longer curfew from Monday.
Bulgaria's capital Sofia, home to some 2 million people, will close nightclubs and discos on Sunday for two weeks.
Germany's health minister expects a COVID-19 vaccine to be available early next year.