The Louvre in Paris, the world's most visited museum, closed to visitors on Sunday after staff refused to work due to coronavirus fears, unions and management said.
Around 300 staff met in the morning and voted "almost unanimously" not to open, Christian Galani of the CGT labour union told AFP, leaving many would-be visitors disappointed.
The Louvre, near the banks of the Seine river in central Paris, received 9.6 million visitors last year, most of them foreigners including Americans, Chinese and Europeans.
Louvre management later confirmed the museum was closed for the entire day, and said it would refund ticket-holders.
"We apologise for any inconvenience and will keep you informed as the situation develops," the museum said on its website.
On Saturday, the government announced several measures to try and curb the outbreak in France, including cancelling all gatherings of more than 5,000 people in confined spaces.
"The Louvre is a confined space which welcomes more than 5,000 people a day," said Galani, adding: "there is real concern on the part of staff."
Workers met in the morning to discuss these fears, and Galani said management representatives were unable to convince staff to go to work.
They are demanding stepped up protective measures, including the provision of hand sanitising gel and window barriers to separate cashiers from members of the public.
In January, workers also forced a one-day closure in a strike over the government's pension reform plans.
Earlier this week, the museum ended a special Leonardo da Vinci exhibition with an all-time visitors' record of nearly 1.1 million people.