WASHINGTON, Jan 12 (Reuters) - Occupy protesters in the U.S. capital may be removed after Washington's mayor said on Thursday their camp in a downtown park poses health concerns to the city and cited a rat infestation.

Mayor Vincent Gray sent a letter to the National Park Service, which oversees the McPherson Square park that has become home to "Occupy DC" - a group of more than 100 protesters camping out in solidarity with the Occupy Wall Street movement, a loose network of Occupy encampments across the country.

Citing a health inspection conducted by a city official that found rats in tents and within the area where food is prepared for the group, Gray said "conditions at McPherson Square are particularly a threat to the health and safety of both protestors and District residents."

Gray called on the National Park Service to take immediate steps and said protesters should be moved to a nearby plaza where another group of protesters has been camping out.

"At a minimum the Occupy DC sites at McPherson Square and Freedom Plaza must be consolidated at Freedom Plaza to allow for elimination of the rat infestation, clean up, and restoration of McPherson Square," Gray wrote. Both sites are only a few blocks from the White House.

The removal of the protesters could be a blow to the national movement. Police have cleared camps in New York; Los Angeles; Oakland, California; and other major cities. Cold weather and internal dissent have contributed to faltering morale in some camps.

Occupy DC has enjoyed a relatively cooperative relationship with the police and is one of the few groups that has not been disbanded.

Washington protesters say they are not concerned yet, partly because a court order they have won requires the police to give the camp 24 hours' notice before an eviction.

"I'm personally not that worried right now. So far, (the park police) haven't seemed like they're looking forward to trying to evict us," said Ricky Lehner, a 23-year-old from Florida who has been at the camp since October.

"All I'm going to say is if they gave us 24 hours notice it would give us time to prepare." (Reporting By Lily Kuo; editing by Mohammad Zargham)