Violence erupted for a seventh night across several parts of the US, just hours after President Donald Trump vowed to use military personnel to halt the protests.
"Mayors and governors must establish an overwhelming law enforcement presence until the violence has been quelled," Trump said.
"If a city or state refuses to take the actions that are necessary to defend the life and property of their residents, then I will deploy the United States military and quickly solve the problem for them."
Following his address, he walked from the White House to nearby St. John's Episcopal Church amid tight security to pose for pictures with his daughter Ivanka.
However, a few hours later, thousands of people marched through the streets of Brooklyn, shouting "justice now!", while demonstrators in Los Angeles and New York City clashed with riot police.
George Floyd, a 46-year-old African-American, was killed minutes after a policeman pinned his neck under a knee for nearly nine minutes.
Hundreds of supporters of South Korea's arrested president, Yoon Suk Yeol, stormed a court building early on Sunday after his detention was extended, smashing windows and breaking inside, an attack the country's acting leader called "unimaginable".
Russian forces unleashed a combined drone and missile strike on the Ukrainian capital Kyiv early on Saturday, killing three people in a central district, officials said.
Donald Trump's incoming US presidential administration plans to intensify immigration enforcement nationwide soon after he takes office on Monday, Reuters reported.
Israel's cabinet approved a deal with Hamas for a ceasefire and release of hostages in the Gaza Strip, Prime Minister Benjamin Netanyahu's office said on Saturday, a day ahead of the agreement's scheduled start.