Two statues of Christopher Columbus were taken down in Chicago early Friday, amid a reckoning in the United States about the Italian explorer's controversial role in the history of the Americas.

The statue in the city's Grant Park -- cloaked in plastic -- came down in the early hours as small groups of onlookers watched.

"It feels great seeing the statue come down," one resident, Brenda Armenta, told AFP.

A second statue of the navigator long hailed as the so-called discoverer of "The New World" came down in Arrigo Park, on the edge of Chicago's Little Italy neighborhood.

Statues of Columbus and other figures connected to colonialism and slavery have been torn from their plinths in the United States and around the world in the wake of protests sparked by the May killing in police custody of George Floyd, an unarmed African American, in Minneapolis.

The office of Chicago Mayor Lori Lightfoot said in a statement carried by local media that the statues had been "temporarily removed... until further notice" at her direction.

The move "comes in response to demonstrations that became unsafe for both protesters and police, as well as efforts by individuals to independently pull the Grant Park statue down in an extremely dangerous manner," it said.

"This step is about an effort to protect public safety and to preserve a safe space for an inclusive and democratic public dialogue about our city's symbols."

The legacy of Columbus, who reached the Americas in 1492, has been revisited with the benefit of hindsight over the brutal treatment of native Americans by European colonizers.

Statues of Columbus have been removed in other cities such as Baltimore, Boston and San Francisco.

But in New York, the state's governor Andrew Cuomo and city mayor Bill de Blasio have ruled out removing one from the circle bearing his name near Central Park.

Cuomo, whose family has Italian roots, says while he understands the negative feelings about Columbus and "some of his acts, which nobody would support," the statue honors the "Italian-American contribution to New York."