Three people "stepped out of the vehicle with assault rifles and handguns and started firing indiscriminately into the crowd", the police director said.
Paramedics pronounced two victims dead on the scene.
The United States has a long and painful history of deadly gun violence, with a steady daily toll of shootings as well as high-profile mass killings that have targeted schools, workplaces and shopping centers.
"These are cold-blooded killers who fired indiscriminately into a crowd", he said, stressing, "We will do justice".
Angelica Green, who told WPLG that her 24-year-old son was among those shot early Sunday, recalled the phone call she received in the moments after the shooting.
At least one victim was transported in critical condition, the statement said.
Police said they're looking for a silver Nissan Maxima that may have been involved in that shooting.
In March a year ago, the number of weekly federal background checks on gun buyers surpassed one million for the first time, the New York Times reported.
It was the second major shooting in the Miami area in as many days.
"This type of gun violence has to stop", Ramirez said.
The incident is the latest of several recent mass shootings in various parts of the country.
Last month, President Joe Biden denounced an "epidemic" that is a source of "embarrassment in the worldwide arena".
Thousands of people are killed by guns in the USA every year.
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