Miami, Florida - Pepper balls, SWAT teams and a military-style vehicle rolling down Ocean Drive became the new picture of spring break on South Beach on Saturday night as Miami Beach police tried to enforce an 8 PM curfew.

The city announced the curfew for South Beach's "High Impact Zone" only hours earlier in reaction to spring break crowds so violently rowdy that Ocean Drive's longest continuously open establishment, The Clevelander, announced Friday it was shutting down until Wednesday.

The curfew, announced as part of a state of emergency declaration made at 4 PM, included the closure of bars and clubs on jam-packed Ocean Drive. People were told to disperse.

On such short notice, curfew compliance clashed with curfew enforcement as was chronicled by social media and news organizations around the world. Thousands of people were still on Ocean Drive and in the city's entertainment district at 8 PM.

To clear them out, videos showed, police turned on their lights and sirens and fired pepper balls into the crowds.

Miami Beach police have used pepper balls to break up crowds of tourists several times since the start of spring break about six weeks ago.

Essentially they are balls that are fired at the ground and emit tear gas, forcing people within a certain distance to move to avoid the eye irritant.

In one instance that is making the rounds on social media, police used the chemical on Saturday night at about 9 PM after a large crowd gathered on 8th Street and Ocean Drive. Visuals of the smoke and visitors racing away in different directions and of police firing the irritant with long guns formed a particularly ugly picture for city leaders during a busy time at one of world's top tourist meccas.

Miami Beach Police Chief Richard Clements, speaking to the Miami Herald specifically about the scenes Saturday night, said his officers fired the tear gas only as the crowd began to surge towards them. He said police wouldn't fire the pepper balls simply to break up a crowd of people.

"I think officers felt threatened at the time," the chief said. "There has to be an element there of either the crowd fighting or coming at officers."

He said Saturday night's incident would be reviewed internally.

Clements also said the crowds seem to be rowdier than in past years and more threatening to police. He said when an officer makes an arrest, crowds of people will often circle the police and challenge the detainment. Clements said an element of that may be related to the death of George Floyd and the sometimes violent protests nationwide that followed.

"The temperament of the crowd is a little different. Venues, pre-Covid, were more plentiful. There are not a whole bunch of places for you to go, now," said the chief. "They're [the crowd] more assertive. When we have an arrest situation, people seem more assertive about not letting that arrest occur. But I don't think that's specific to us."

Clements said the tactics his officers have used to break up spring break crowds have been because of violent and dangerous behavior and has nothing to do with the global pandemic.

"Nothing we have done to this point to break up crowds has been because of Covid," the chief told the Miami Herald Sunday afternoon.

Though this year's crowds have been large, they mostly pale in comparison to the swell of visitors the city has received the past few decades during Memorial Day Weekend. To combat that surge, the city began implementing a major event plan a few years back that included altering the direction of some streets, having corrections staffers on site to process arrests and having most officers work during the busiest hours.

But, Clements said, with spring break lasting closer to eight weeks than the three or four days the crowds visit during Memorial Day, implementing the plan isn't feasible.

"You can't have Alpha Bravo for six weeks," Clements said. "That's too long, almost debilitating."

Miami Beach police couldn't immediately provide the number of times officers fired pepper balls, and the department said it couldn't provide arrest numbers until Monday.

Police spokesperson Ernesto Rodriguez said about twice as many people have been arrested compared to last year. The city has said it has made about 1,000 arrests since the first week of February. They have also seized about 80 firearms, including four on Saturday night.

Clements, who said he was "alarmed" by the number of firearms he's seeing, said most of the problem seems to be that people who drive here are bringing weapons down from open carry states, where they are permitted.