An arrest has been made in the incident outside the building where a dozen people were gunned down in 2015 in apparent retaliation for the publication of cartoons that satirized the Prophet Muhammad.

"We are in a period of epidemic growth," Prime Minister Jean Castex said. "We want to do everything to avoid a new lockdown." The order goes into effect Friday.

One museumgoer says it's a "much more comfortable experience" to view the Mona Lisa without the mobs of tourists. The Louvre put in place mask-wearing, one-way paths and other distancing measures.