The Louvre Museum remained closed on Monday after staff voted in favor of a strike over pay, staffing levels and working conditions, disrupting access for thousands of visitors to the world’s most-visited museum.

The walkout, supported by around 400 employees and announced by union representatives, comes at a challenging moment for the Paris landmark. The museum is still dealing with the fallout from an October jewel heist valued at 88 million euros ($103 million) as well as recent infrastructure problems, including a water leak that damaged ancient books.

“Due to public strikes, the museum is currently closed,” the Louvre said in a notice posted on its official website.

The strike was called by the CFDT, CGT and Sud unions, which said working conditions at the museum have “significantly deteriorated” in recent years due to chronic understaffing and rising visitor numbers.

In a joint statement, the unions said employees face “an ever-increasing workload” and “contradictory instructions” that prevent them from properly carrying out their duties, particularly in security and visitor services.

Union demands include the recruitment of more permanent staff, improvements to working conditions and guarantees on safety standards. The unions have also voiced opposition to a planned 45 percent ticket price increase for non-European Union visitors starting in mid-January, a move the museum says is intended to help finance renovation projects.

The Louvre typically welcomes about 30,000 visitors per day, making the closure a major disruption during the peak tourism season.

Museum officials have not yet indicated when normal operations will resume.