MIAMI, DEC. 3 -- Residents of a poor Puerto Rican neighborhood looted several buildings and set fire to three tonight in a disturbance protesting the acquittal of six Miami police officers in the beating death of a suspected drug dealer.

About 200 residents moved into the streets shortly after sundown when a group of Hispanic youths wearing bags over their heads began throwing rocks and bottles and breaking windows. The youths set fire to a building, an abandoned home and a storefront, and rolled over a car and set it ablaze. About 300 Miami police moved in to quell the violence, reporting 10 arrests and a few injuries among the youths, apparently none serious, before the violence subsided about 11:30 p.m.

Earlier in the day, a federal jury acquitted six Miami undercover policemen on conspiracy charges in the beating death of Leonardo Mercado, 35, in December 1988. Most of the disturbance occurred near the home of Mercado, a Puerto Rican.

The incident came as city officials are working to defuse tensions in Miami's black community. Black activists have mounted a successful boycott of Miami's convention business, costing the city millions, and have threatened to take the boycott nationwide. Blacks here are also angry at city leaders for snubbing African leader Nelson Mandela when he visited Miami last June.

Today's outbreak occurred after Mercado's girlfriend vowed to avenge the jury's verdict. One demonstrating youth, explaining his actions to a television interviewer, said the blacks of Miami made TV news whenever they resorted to violence, and now these protests would too.

Prosecutors in the policemen's trial said the six officers, part of the Miami Police Department's elite narcotics unit, tracked down Mercado at his home and questioned him about an anonymous death threat made against one of them, Pablo Camacho.

Prosecutors said the officers were overzealous in dealing with Mercado. Evidence introduced in the trial showed that treadmarks from the bottom of some of the officers' sneakers matched patterns on Mercado's forehead and clothing.

The jury was unable to reach a verdict on the principal charge that the victim's civil rights had been violated. U.S. Attorney Dexter Lehtinen said his office would consider retrying the policemen on that charge.