Police in Miami Brace for Violence : Race relations: Two Latino officers shoot and wound a black man. The incident threatens to spark a new round of rioting.

MIAMI —  Police in riot gear remained on alert and braced for possible violence Friday after a police shooting Thursday night set off sporadic incidents of rock- and bottle-throwing in two predominantly black neighborhoods.

Two Latino officers on routine patrol shot and wounded a black man who they said was walking toward them with a gun. The incident came just two days after a state appeals court ordered a new trial for another Latino Miami policeman, William Lozano, convicted of manslaughter in the shooting deaths of two black men in 1989.

But after a day of calm Friday, Miami Police Chief Calvin Ross downplayed the level of tension in the community, blaming outbreaks of violence on “a group of thugs.”

The Thursday shooting took place after police responded to reports of a gunfight in the Overtown section, just north of downtown Miami. Officers Serafin Ordonez and Jorge L. Garcia said that as they approached the scene on foot, a man later identified as Charlie Brown came toward them with a gun. The officers fired two shots, a police spokesman said, and Brown was wounded in the right side.

Brown’s mother, Oreatha Witherspoon, said that her son was moving toward the police officers for protection because someone was shooting at him. He had his hands up, she said. “Then I heard the gun, bam, and my son fell,” she said.

Police said that Brown, 30, has a long criminal record that includes drug, weapons and robbery charges. He refused treatment at the scene but was taken to the hospital, where he was reported in good condition Friday. He has been charged with aggravated assault.

Within an hour of the shooting, a crowd gathered and began to throw rocks and bottles at police and firefighters searching a storm sewer for the gun reportedly tossed away by Brown. Riot police, already on alert after the Lozano decision, responded in minutes, sealing off several blocks of Overtown and, later, the main street through the Liberty City section, some three miles away.

A police mini-station in Overtown was trashed, and up to 25 people, including 14 juveniles, were arrested during the night in connection with several incidents, police said. Three police officers were injured, including one who was hospitalized after being hit in the head with a rock.

“A lot of people think this is the black community reacting,” said police spokesman David Rivero. “No, these are the criminals of the black community acting this way.”

Police reported that a gun was recovered from the shooting scene.

Also Friday, organizers of a convention boycott of Miami marked the first anniversary of African nationalist leader Nelson Mandela’s controversial visit here with a press conference to announce that a 16-minute videotape comparing conditions in Miami to those of Selma, Ala., in the 1960s has been sent to tourism officials in several U.S. cities.

As the video contrasts palm-shaded waterfront mansions with barren residential landscapes of the inner city, a narrator says: “As a result of police brutality against blacks, Miami is the only city in the nation that has experienced three major riots in the last decade.”

The boycott began last July to protest what organizer H. T. Smith calls the way local elected officials “shamefully and disgracefully snubbed Mr. Mandela” by refusing him a welcoming proclamation and keys to the city. Several area Latino leaders refused to honor Mandela because he had thanked Cuban President Fidel Castro for his support during Mandela’s long jail term in South Africa.

At least 10 national organizations, including the National Assn. of Black Social Workers and the American Civil Liberties Union, have canceled conventions in Miami. Smith said that the overall value of the business lost because of the boycott exceeds $27 million.