NEW YORK, NY.- As the omicron variant overtakes the country, and coronavirus cases reported for the last week in the capital region climbed to their highest number since the start of the pandemic, the Smithsonian Institution said this week that it would temporarily shutter five of its museums.

The biggest among them is the National Museum of Natural History, which will close Thursday and Friday and is scheduled to reopen Jan. 5. The museum is normally closed Mondays and Tuesdays. Linda St. Thomas, a spokesperson for the Smithsonian, said Wednesday that the museum was experiencing a shortage of visitor services staff. The line to enter the museum was at least an hour long Wednesday, she said.

“The additional closure of the National Museum of Natural History will allow the Smithsonian to reallocate staff and keep all other museums open for the remainder of the week,” the museum said in a statement Wednesday.

The Smithsonian had previously announced that the National Museum of African Art, the National Postal Museum, the Anacostia Community Museum and the National Museum of Asian Art (Freer Gallery of Art and Arthur M. Sackler Gallery) would close Wednesday through Sunday and reopen Monday.

“Like many other organizations, the Smithsonian has been managing the direct and indirect outcomes of the latest surge in COVID infections caused by the omicron variant,” the Smithsonian said in a statement posted on its website Tuesday. “Over the last few days, the Smithsonian has seen an increase in positive COVID cases and associated quarantine periods among our essential and operational staff.”

The Smithsonian said that the closure of the four smaller museums, which have lower attendance rates, would allow it to keep larger institutions open by moving guards and other essential staff.

A number of museums across the country have also been grappling with recent coronavirus-related closures. Some in New York, Maryland and several other states announced plans to shut again.

In New York, the Metropolitan Museum of Art announced last week that it would limit attendance to about 10,000 visitors per day because of the highly contagious omicron variant; and the Winter Show, a long-standing New York art, antique and design fair, postponed its Jan. 20 opening at the Park Avenue Armory.

In Queens, the Noguchi Museum has closed through Tuesday; and in New Haven, Connecticut, the Yale University Art Gallery and Yale Center for British Art have both closed through Sunday. The Baltimore Museum of Art reopened its galleries Wednesday morning after closing last week because of the spread of COVID-19.

Other museums have remained open but implemented new restrictions. The National Gallery of Art in Washington and the Brooklyn Museum, for instance, have canceled many in-person tours.

Like the rest of the country, the nation’s capital has seen a surge in cases this month: 1,868 new coronavirus cases were reported in Washington on Tuesday, and the average of 2,071 daily cases was a 931% change from the figure two weeks earlier.

The closures come in the week between Christmas and New Year’s, when attendance figures would typically be among the highest of the year.

This article originally appeared in The New York Times.