WASHINGTON, Aug. 24 -- U.S. National Park Service (NPS) said on Wednesday that it has indefinitely closed the Washington Monument, which was damaged after Tuesday's earthquake.

"The Washington Monument, because of its structural complexities, will remain closed until further notice," said a statement from the NPS. The monument, a 170-meter-high obelisk, was found to have some cracking in the stones at the top.

The NPS conducted inspection on several monuments around the National Mall after the magnitude 5.8 earthquake struck the region on Tuesday afternoon, and the Lincoln and Jefferson Memorials were reopened to the public later in the evening.

The NPS said structural engineers were evaluating the cracks on Wednesday to determine the best way to repair the Monument before it is reopened. The Washington Monument grounds have been reopened except for an area about 100 feet outside of the plaza.

The Martin Luther King, Jr. Memorial, Franklin Delano Roosevelt Memorial, the World War II Memorial, Vietnam Veterans Memorial and the Korean War Memorial remain open. The Old Post Office Tower opened on Wednesday morning.