A group of students from Plantation High School in Florida participating in the Mentoring Tomorrow’s Leaders program pose for a photo with the Martin Luther King Jr. Memorial on the National Mall on January 19, 2014 in Washington. On Monday the United States will honor the birth of civil rights leader Martin Luther King.(Photo: AFP/Getty Images)

WASHINGTON — A section of rope was found near the MLK Memorial in Washington on Friday, two days after a noose was discovered inside the National Museum of African American History and Culture, U.S. Park Police said.

The piece of rope was found on a bench at the memorial on near the National Mall. A visitor turned it in at the memorial’s bookstore.

Police did not release any further information.

On Wednesday, a noose was found inside the Smithsonian Institution’s National Museum of African American History and Culture.

“The noose has long represented a deplorable act of cowardice and depravity — a symbol of extreme violence for African Americans,” said Lonnie Bunch, the director of the African American history museum.

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Park Police investigators have surveillance video from inside the museum, but a spokesman would say what, if anything, the agency found.

Last week, a noose was found hanging from a tree outside the Hirshhorn Museum and Sculpture Garden, also on the National Mall. That incident is also under investigation.

Smithsonian Secretary David Skorton said in a letter to African American history museum employees after Wednesday’s incident, “We will not be intimidated.”

“With new urgency, we will tell the story of our nation and all its people. We will continue to fight this sort of ignorance with knowledge,” Skorton said. “We will remain vigilant and, in spite of these deplorable acts, we will become a stronger institution for all Americans.”

Contributing: USA TODAY