PARIS – Paris’ Louvre museum was closed Friday as dozens of protesters blocked the entrance to denounce the French government’s plans to overhaul the pension system.

The Leonardo Da Vinci exhibit marking the 500th anniversary of the Italian master’s death, which is displayed at the Louvre, was also closed as a result, the museum said.

Several dozen protesters, including some Louvre employees, staged the demonstration after an appeal from several hard-left trade unions against President Emmanuel Macron’s planned changes to the retirement system, which they said will “lower everyone’s pensions.”

Some protesters were singing “Mona Lisa in on strike, Leonardo is on strike.”

It is the first time since the protest movement began on Dec. 5 that the Louvre and the Leonardo exhibit were fully closed. About 30,000 people visit the museum every day.

Some videos on social media showed angry visitors booing at protesters to express their disappointment.

The weeks of strikes and protests have hobbled public transportation and disrupted schools, hospitals, courthouses and even opera houses and the Eiffel tower.

Major French retailers Fnac Darty and Casino said that business in France was badly affected by the strikes, especially during the holiday season.

Fnac Darty said the strikes cost it around 70 million euros ($78 million) in lost revenue.

Casino cut its forecast for earnings growth in France, where it does more than half its business, to 5% in 2019, from a previous 10%. The company estimates that the strikes in December cost it about 80 million euros in lost revenue .

Shares in both companies were down by more than 5%.

While the number of striking workers has diminished since the movement, the country’s trains and the Paris subway were still disrupted Friday.