Police to investigate placement of rope meant to represent ‘deplorable’ and ‘coward’ lynching of African Americans.

US police have launched an investigation after a noose was found in a public exhibition space of the Smithsonian National Museum of African American History and Culture in Washington, DC, the second such incident in less than a week.

David Skorton, secretary of the Smithsonian Institute, said in a statement that the rope was found by tourists on Wednesday on the floor of the Segregation Gallery of the National Museum of African American History and Culture (NMAAHC).

NMAAHC, which opened last September in a ceremony that included then-President Barack Obama, is the only national museum in the US devoted exclusively to documenting African American life, history and culture.

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Museum Founding Director Lonnie Bunch III said in a statement that the noose represents “a deplorable act of cowardice and depravity” and serves as “a painful reminder of the challenges that African Americans continue to face”.

A statement from our Founding Director Lonnie Bunch on the noose found in our history galleries today. pic.twitter.com/sFWVSaobhV — Smithsonian NMAAHC (@NMAAHC) May 31, 2017

This was the second such incident in less than a week at a Smithsonian Institution museum. A noose was found hanging from a tree outside the Hirshhorn Museum on Friday.

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In the US context, the noose is meant to represent lynchings of African Americans that took place primarily from the 1860s to the 1960s.

These lynchings usually consisted of mobs of white Americans swarming one or a small group of African Americans and killing them, before tying a rope around their neck and hanging them, often on trees.

The mobs would frequently accuse the targeted individuals of having committed some crime without proof. In many cases, the mobs would target random African Americans on the street or mistake one individual for another before killing them.

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Since the decline of mob lynchings in the US, African American activists have continued to shed light on violence faced by members of their communities, particularly most recently at the hands of law enforcement.

But activists have also highlighted rhetoric used by President Donald Trump as incitement for ordinary citizens to express anti-immigrant, anti-Muslim and anti-African American sentiment publicly.

Since Trump’s inauguration, nooses have been found hanging in schools and universities across the country.