Four people were arrested in North Philadelphia Friday night after protests turned violent, resulting in three police officers being injured, according to local police.

About 100 people gathered across the street from City Hall to protest against police abuses. Protesters began blocking traffic, and a violent clash with officers broke out.

Police said the three officers suffered minor injuries after being hit with pepper spray and black spray paint.

Video footage shows the protesters burning an American flag. Those arrested are facing assault charges.

Milwaukee County Sheriff David Clarke joined "Fox & Friends Weekend" Saturday morning to discuss these violent protests.

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"This stuff is disastrous. It's going to get cops hurt; it's going to get cops killed," Clarke said.

The sheriff said he wants to see cops advance as soon as vandalism and violence break out at these types of protests, since it is impossible in large crowds to determine exactly who is causing the commotion.

"It is unreasonable for us to determine who are the peaceful protesters and who are the resistors," Clarke said. "This is a resistance movement."

Watch the clip from Clarke's interview above, and share your thoughts on his remarks and these violent protests in the comments section.

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