Large crowds on the US city’s party strips prompted an emergency overnight curfew.
Miami Beach Mayor Dan Gelber said thousands of tourists had brought “chaos and disorder” to the city.
“It feels like a rock concert, wall-to-wall people over blocks and blocks,” Mr Gelber told CNN. “If you’re coming here to go crazy, go somewhere else.”
Spring break is a holiday period for schools and universities in the US that usually takes place in March or April. It attracts thousands of students to Florida and other warm-weather destinations around the country.
Officials warned tourists to “vacation responsibly or be arrested” prior to the holiday period, and a county-wide midnight coronavirus curfew was already in place due to the pandemic.
But the Miami Beach area was thronged with revellers over the weekend, and many did not appear to be wearing masks or socially distancing.