The Minneapolis-based firm that was providing security at Super Bowl Live was replaced Wednesday for insufficient background checks of its employees, according to sources familiar with the situation.

The Super Bowl Host Committee replaced EPG Security Group with G4S, another Twin Cities firm, sources said Friday.

Host committee spokeswoman Andrea Mokros declined to provide information about how the problem was discovered, how many EPG employees were involved or what their duties were.

But Minneapolis police Lt. Bob Kroll said that the site that EPG was guarding was left shorthanded after several of its officers were yanked away by federal authorities. Mokros declined to comment on that characterization.

Super Bowl Live on Nicollet Mall between 6th and 12th streets is the showcase event produced by the host committee, consuming a major chunk of the $52 million they say they have raised in private funds. More than 100,000 visitors were expected at the event, which has seen good crowds for nightly concerts and activities.

There have been no significant security problems with the event that started Jan. 26 and goes through Sunday.

A security guard stood in front of the stage at the Super Bowl Live events on Friday night, February 2, 2018, on Nicollet Mall in Minneapolis, Minn.

Most of the visible security effort on the mall involves crowd control. Bag checks are conducted to access certain parts of the concert-viewing area, but visitors aren’t required to pass through metal detectors.

The event is open access, with no main security entrance, and most streets have remained open for cross traffic. During peak hours, licensed police officers also assist.

In a statement, Mokros said, “Safety and security is and always has been our top priority. We don’t comment on the security measures in place except to say that all efforts are part of an integrated, multilayered partnership with all levels of law enforcement. We are confident that the security measures in place are appropriate and effective.”

EPG was similarly opaque. The company issued an unattributed written statement that read, “We are not at liberty to comment on changing security strategies and assignments.”

EPG, founded in 2007 by former Marine Erik Bergling, has deleted its various social media accounts: Instagram, Facebook and Twitter. But a cached version of an Instagram post said the firm was “hiring hundreds of protective agents for two major upcoming events in the Twin Cities: Red Bull Crashed Ice and Super Bowl Live.”

The firm provided security at Donald Trump’s inauguration and the 2016 Republican National Convention in Cleveland, both high-security events, according to its blog. Clients have included area bars and theaters.

Kroll said that the backgrounding problem was discovered by federal agents. “It was a credential issue that the feds had with a security guard and then they ran some checks,” said Kroll, who heads the city’s police union. “… He was a convicted felon, and then they did checks on other guys.”

G4S staff on the mall Friday evening and most licensed police officers, who didn’t want to be quoted, hadn’t noticed security problems beyond public drunkenness.

Others said they did not know the firm was fired.

Minnesota National Guard members Dayton Dekam and Jake McCalla, who were wandering through the crowd in uniform, were surprised.

“We’re just doing what we’re told,” McCalla said.

A G4S security guard, who asked not to be identified because he did not have permission to talk to the press, said the company sent staff from across the country, including Georgia, North Carolina and Florida, to work Super Bowl Live and that they have been on duty since last weekend.

Tyler Clark, who has been working at the event handing out hot chocolate, said he’s felt safer than usual all week and that law enforcement has quickly responded to issues.

There are so many law enforcement agencies that Clark, who lives in Minneapolis, said he had not noticed EPG’s disappearance. “You can’t tell,” Clark said.

EPG was not involved in security at U.S. Bank Stadium or NFL sites such as the Super Bowl Experience at the Minneapolis Convention Center — just the activities on Nicollet Mall.

U.S. Bank Stadium had a similar problem last year. The Chicago-based firm providing its security was fired after an investigation revealed inadequate background checks, training and sloppy recordkeeping.