CHICAGO (CBS) — As protests over the death of George Floyd turned violent Saturday night, Mayor Lori Lightfoot announced a curfew in Chicago from 9 p.m. to 6 a.m. until further notice.

“What started out as a peaceful protest has now devolved into criminal conduct. We have watched these protesters hurl not just words, bur projectiles at our police department; bottles of water, urine, and Lord knows what else,” Mayor Lightfoot said.

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The mayor also said shovels, bats, hammers, and lead pipes were wielded against officers.

Mayor Lightfoot praised those who expressed their First Amendment rights, but also expressed disappointment, and “really, my total disgust,” at those who came to the protests downtown “armed for all-out battle.”

“I’m here to call you out for your recklessness, for your obscene disrespect to the cause that you are trying to hijack,” the mayor said.

An emergency wireless alert was issued when the curfew began at 9 p.m.

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“The curfew is enforceable by law and restricts people from remaining in any public place – including but not limited to streets and highways, and common areas of schools, hospitals, office buildings and shops; or on the premises of any establishment – defined as any privately owned business operated for a profit to which the public is invited, within the City of Chicago during curfew hours,” the Mayor’s office said.

People engaged in essential activities as defined in the Municipal Code, Order 2020-3 are exempt.

The Chicago Police Department will enforce the curfew through measures including warnings, fines and/or arrests, the city said.

Those who need to return home from the Loop may exit by foot or vehicle through the South Loop or the LaSalle Street bridge, or access the Chicago Transit Authority outside the Loop.

Floyd was handcuffed when he begged for air as a Minneapolis police officer pressed his knee on Floyd’s neck.

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On Saturday in downtown Chicago, protesters looted stores, set fire to squad cars, and scuffled with officers before the mayor announced the curfew.