Gross misdemeanor riot charges were filed Monday against 46 adults in connection with the overnight protest Saturday and early Sunday on Interstate 94 in St. Paul in response to Wednesday’s police shooting of Philando Castile.

Only one person — a 37-year-old St. Louis Park man — has been charged with a felony, for second-degree riot, for allegedly throwing rocks and construction debris at police. Twenty-one officers were injured, including a University of Minnesota officer who initially was said to have suffered a broken vertebra. That officer’s diagnosis was upgraded Monday; the department said in a tweet that he “received a spinal compression injury.”

Other felony charges are likely to follow, said a spokesman for the Ramsey County attorney’s office.

Another three or four dozen people were ticketed for misdemeanor unlawful assembly and public nuisance early Sunday at Dale Street and Grand Avenue, where they gathered after the I-94 protest. One juvenile also is expected to be charged with gross misdemeanor third-degree riot.

Those charged were among an estimated 500 people who blocked the freeway in both directions near the Lexington Avenue exit. Police made 20 announcements over a loudspeaker, asking the crowd to disperse, and used smoke bombs and ultimately tear gas and a chemical irritant to get the protesters off the roadway and surrounding fences and hills.

Bail was set at $1,500 on Monday for each of those charged with gross misdemeanors; each faces three charges: third-degree riot, public nuisance and unlawful assembly. They began posting bail and trickling out of the jail about 6:15 p.m. Monday. Many will make their first court appearances Tuesday.

Bail for Louis B. Hunter was set at $50,000. He is charged with two counts of second-degree riot armed with a dangerous weapon. According to the criminal complaint, officers saw him throw rocks and debris at officers, then pick up a 6-foot length of wood and carry it around in the crowd.

An officer hit him in the pants with a green marking round and arrested him when he returned to his vehicle after the protest, the complaint said. The document said Hunter told police he was hit by the marking round “almost as soon as he arrived on the freeway and for no apparent reason.” He denied throwing any objects.

Lena Gardner, an organizer with Black Lives Matter Minneapolis, was outside the Ramsey County jail Monday evening. She said she doesn’t know how many people posted bail and wouldn’t comment on the criminal charges. She reiterated that BLM Minneapolis does not condone violence.

“Our movement is under attack right now from government officials who are more interested in criminalizing protesters than they are in addressing the issues that took Philando Castile’s life,” Gardner said.

St. Paul police spokesman Steve Linders said his department does not believe Black Lives Matter St. Paul “started, endorsed or condoned” the violence directed at the officers and noted that one of its leaders tried to halt violent actions.

Police Chief Todd Axtell said St. Paul police “have always had a great history” with “our protest community, working together the best we can.

“We will never agree on everything … but it’s always been cordial, even though defiant at times,” the chief said. “But it’s never been violent like this, and that’s what caught us off guard on Saturday evening when our officers came under attack. We adjust our response based on the actions of those who decide to assault our officers.”

St. Paul police do appear to have reached “a threshold” with protesters who have been camped out outside the governor’s residence in St. Paul since the shooting.

“Residents should have access to their homes,” Axtell said Monday. “They should have the ability to sleep at night without chanting and loud noises. Those are factors I consider when enough is enough.”