Extra security fanned out around the Mall of America on Wednesday in a show of strength designed to prevent a repeat of last year's day-after-Christmas melee involving dozens of teenagers and young adults at the iconic mall.

Last year's disturbance, the worst violence to hit the mall in 15 years, drew national attention when footage surfaced on YouTube. Earlier that day, rumors spread on Twitter and Facebook that rap stars Lil Wayne and Drake were going to perform at the mall, attracting crowds of teenagers and young adults.

This year, the mall's 150-strong security force beefed up patrols, mostly to enforce an expanded policy that requires people younger than 16 to be escorted by someone 21 or older from 4 p.m. to close. The policy, rolled out over Black Friday weekend, will be in place until the end of the year, mall spokesman Dan Jasper said.

Bloomington police also posted additional officers inside and outside the buildings. "Whenever you can build accountability into the minds of parents whose children want to go to the mall, that only helps us," said Cmdr. Vic Poyer, a spokesman with the Bloomington police.

Aside from a minor fight in the food court, Jasper said, Wednesday was calm.

In last year's disturbance, a fight that broke out in the food court escalated, with people hurling chairs and fighting. The violence eventually spilled outside as police officers and security guards struggled to contain it.

MOA officials initially suspected the incident was organized through social media, though police later downplayed that possibility. Adding to the confusion was the mall's initial decision to lock down the property, which it quickly reversed. Eventually, some stores closed early on one of the year's busiest shopping days.

After reviewing its security procedures, mall officials decided to expand a parental escort policy, Jasper said. In addition to extra guards, the policy is meant to deter youths from gathering and loitering unsupervised in large groups.

But one firm that specializes in mall security issues said that approach can be difficult in practice, since the majority of young people behave and legitimately shop at stores.

The policy looks "good on paper but it does little to deter those acts of violence," said Steve Cina, an executive with IP Video Corp., which provides high-definition surveillance systems to malls, government buildings and schools. "It's hard to pigeonhole people."

IP Video President David Antar said people in their late teens to mid-20s commit the bulk of violent crime at malls vs. kids younger than 16, the target of Mall of America's policy. Indeed, eight of the 10 people arrested after the fight last year were at least 17 years old.

Thomas Lee • 612-673-4113