Thousands of demonstrators jammed the Mall of America rotunda Saturday as part of a national day of protest, disrupting the Twin Cities largest retail center on one of the busiest shopping days of the year.

After a half-hour that included chants and the song "I Can't Breathe," mall management warned participants in the Black Lives Matter event that they were trespassing and in danger of arrest. A few dozen Bloomington police officers wearing riot helmets then peacefully cleared most of the crowd — estimated between 2,000 and 3,000 people — from the rotunda and tried to block them from the rest of the mall's ground floor.

But hundreds of protesters quickly migrated to shopping areas adjacent to the rotunda, occupying two levels and staging several "die-ins" in front of stores. It took more than two hours before the mall was returned to normal, with a number of stores on its east side shut down for part of that time. Some shoppers were kept inside stores they were visiting until the area had been cleared of protesters.

A number of people were seen being escorted away by police, their hands zip-tied behind their backs. By Saturday night, Bloomington police said a total of 25 people had been arrested.

The protest capped several weeks of rallies in the Twin Cities and across the country in reaction to the decisions by grand juries not to issue indictments in the deaths of unarmed black men in confrontations with police in Ferguson, Mo., and New York. Twin Cities rallies had previously shut down traffic on busy roads in St. Paul and Minneapolis, and brought demonstrators inside Minneapolis City Hall.

But the Mall of America represented the protesters' highest-profile action yet.

A text from BlackLivesMpls, sent just before 3 p.m., exulted: "We shut it down y'all … Great work!"

On the Black Lives Matter Facebook page, organizers claimed that more than 3,000 people had gathered at the mall. "The police and security shut down the ENTIRE mall for hours — amazing work everyone!" said a statement on the page.

Mall officials said all areas of the shopping center were reopened to the public before 5 p.m. In a statement, they expressed frustration with the protesters.

"We are extremely disappointed that organizers of Black Lives Matter protest chose to ignore our stated policy and repeated reminders that political protests and demonstrations are not allowed on Mall of America property," mall officials said. "It's clear from their actions that these political activists were more concerned about making a political statement and creating a media event than they were about the safety of others, who came to Mall of America for an afternoon of shopping and family entertainment."

Hundreds of the demonstrators had chanted, "While you're on your shopping spree, black people cannot breathe" — a reference to the death of Eric Garner in New York after being placed in a choke hold by a police officer.

Tyler Davis, 22, of Chaska, one of the protesters, said he had come to stand for "unity, equality, all of the above. We need to come together."

The overflow crowd and the dozens of police made for an unusually tense scene amid the Christmas decorations on the last weekend of shopping before the holiday. More than two hours after the protest started, police still had several areas blocked off as officers roamed the mall looking for stragglers. Outside, a phalanx of Bloomington police blocked the east entrance to the mall and the parking ramp, forcing shoppers to wait or find alternate places to park.

As the crowd began to build in the rotunda, just before 2 p.m., organizers passed out leaflets to shoppers in a sign of solidarity with other protests across the nation. In Milwaukee, more than 70 people were arrested Saturday morning after shutting down freeway traffic. A small "die-in" was reported outside the Lenox Square mall in Atlanta, and similar disruptions occurred in Charlotte, N.C., and Bellevue, Wash.

The Mall of America was expecting a large crowd after more than 3,000 people confirmed their intent to attend on the organizers' Facebook page. Mall security was in full force, with guards posted and other mall staff checking bags at each entrance.

The mall had said that a demonstration there would violate its policy, and protesters could be removed, arrested and banned. It was not clear Saturday evening if anyone had been barred from the mall as a result of the protest.

"We have a long-standing policy banning political demonstrations and protests on our private property. That policy is in place to protect the safety of all Mall of America guests. The organizers of today's protest were well aware of that policy and the potential consequences for willfully violating that policy," mall officials said. "While we respect the rights of free speech and peaceful assembly, those rights do not trump our right as private property owners to prohibit that behavior on our property — a position that courts have affirmed — nor our responsibility to provide a safe environment for other Mall of America guests."

Organizers had told participants that security workers would search people entering the mall and possibly stop large groups, so protesters were advised to arrive without signs and enter the mall individually or in small groups. The group already had a bail fund set up for anyone who was arrested.

On Saturday morning, the group publicly thanked Minneapolis City Council Members Cam Gordon and Alondra Cano for writing letters on their behalf to mall management.

"There is a national surge of attention on the numerous deaths of African-American fathers, young adults and children at the hands of police officers. Unfortunately, our region has also seen its share of this impact on our Minneapolis-St. Paul and suburban region," Cano wrote. "In other words, Minnesotans are not immune to this hurtful pattern.

Staff writers Nicole Norfleet, Elizabeth Sawyer and the Associated Press contributed to this report. James Walsh • 651-925-5041