MINNEAPOLIS - Four men were charged Monday in last week's shooting of demonstrators protesting the killing of a black man by Minneapolis police, while the city's mayor separately asked the protesters to end their weeks-long encampment at a police precinct.

Protesters have been at the Fourth Precinct since Jamar Clark, 24, was shot Nov. 15 during what authorities said was a struggle with police. Clark died the next day. Some who said they saw the shooting allege he was handcuffed, which police dispute. State and federal investigations are underway.

Protesters have erected about two dozen tents and canopy shelters at the police station, and they have barricaded the street with lumber and pallets. During a snowy Monday morning, about seven campfires were burning to warm those who were milling about.

Minneapolis Mayor Betsy Hodges said Monday that the encampment has become unsafe. She said campfires are making the air harmful to neighboring children and older people with respiratory problems, and the barricades are blocking access for emergency vehicles and snowplows.

But protesters have vowed to stay at the precinct despite the cold weather and last week's shooting that left five black men with injuries that weren't life-threatening. One of the injured men, Wesley Martin, said protesters would stand their ground.

"They can have the street. We can take the sidewalk," Martin said. "To be honest, we're not going nowhere."

Allen Lawrence Scarsella, 23, of Lakeville, was charged Monday with five counts of assault with a dangerous weapon and one count of riot in last week's shooting. Three other men - Nathan Wayne Gustavsson, 21, of Hermantown; Daniel Thomas Macey, 26, of Pine City; and Joseph Martin Backman, 27, of Eagan - were also charged with riot.

Hennepin County Attorney Mike Freeman said he filed the toughest charges possible in what he called a racially motivated attack, saying the felonies carry tougher potential sentences than any kind of hate crime-related charge. Police have said Scarsella, Gustavsson and Backman are white, while Macey is Asian.