Protesters in Baltimore hurled rocks at police, destroyed at least two patrol cars and looted a store as demonstrations escalated Monday over the death of a black man in police custody.
Police said seven officers were injured.
Dozens of people could be seen throwing bricks, rocks and other objects at officers, just hours after funeral services for Freddie Gray. Some demonstrators attacked a stopped police car, leaping on the roof and hood and smashing windows. Minutes later another police car was engulfed in flames.
Baltimore police said on Twitter, "The group is destroying the police car.'' Moments later, police officers moved in and took down several people near the damaged car.
A group of people "is now looting a store in the area of North Ave and Pennsylvania Ave.,'' police said on Twitter. They urged citizens to avoid the area. Aerial video from local TV news showed a crowd entering a pharmacy.
Baltimore police Capt. Eric Kowalczyk said seven officers were injured. He said one officer was "unresponsive'' and others had broken bones. He condemned "criminals who violently and without provocation attacked our police officers.''
He said officers would respond with tear gas and "pepper balls."
"We will continue to keep the city safe,'' he said.
Numerous police officers in riot gear responded to the demonstrations near a mall in northwest Baltimore.
A flier circulated on social media called for a period of violence Monday afternoon to begin at the Mondawmin Mall and move downtown toward City Hall, Associated Press reported. Outside the mall, a young person threw a flaming trash can at the line of officers.
The University of Maryland Baltimore shut down its campus, hours after city police announced a "credible threat" that local gangs were targeting police officers.
The police department said the Criminal Intelligence Unit had obtained information indicating "members of various gangs including the Black Guerilla Family, Bloods andCrips have entered into a partnership to 'take out' law enforcement officers."
The department said law enforcement agencies and officers should take appropriate precautions. It was not clear if the threat to officers was directly tied to the concern for safety at the school.
The campus shut down at 2 p.m. "at the recommendation of the BPD." The school cited unidentified "activities (that) may be potentially violent and UMB could be in the path of any violence.
"The safety of our students and employees is of paramount importance please vacate the campus as soon as possible."
The schools alert was issued shortly after the funeral of Freddie Gray, which drew thousands of mourners to the downtown Baltimore church.
Gray's death April 19 while in police custody set off a week of protests. Most of the protest were quiet — until Saturday night. That protest began peacefully with more than 1,000 people rallying at City Hall. Police Commissioner Anthony Batts said he moved through the crowd, promising that his office was making systemic changes.
Batts, who is black, said the organized protest had essentially wrapped up when tense confrontations resulted in violence. He has blamed the violence on "agitators."
The protesters "became very violent. They began to throw objects," Batts said Saturday night. "They picked up aluminum barricades and smashed windows at our bars and pubs."
Patrol cars were smashed. Six police officers suffered minor injuries; 34 people were arrested.
Batts said some residents moved between police and the angry crowd, urging the protesters not to damage the city. He commended police officers for showing "tremendous restraint" and city residents for helping tamp down the unrest.
"I am proud of our residents and our police officers," Batts said. "The vast majority of residents out here did a good job. ... A small number of people felt like they had to turn this into an ugly day."
Contributing: Associated Press