(Reuters) - Nearly five dozen people were arrested in a Minnesota undercover sting operation for attempting to meet up with children for sex or for sex-trafficking of minors during last weekend’s NCAA Final Four basketball tournament, authorities said on Wednesday.

Undercover agents from dozens of agencies in Minnesota spent Friday through Monday posing as children or sex buyers on various social media platforms. The agents chatted with suspects online and then arrested them when they arrived at an arranged meeting place for an encounter, the Minnesota Department of Public Safety said in a statement.

A total of 58 suspects were taken into custody, while 28 victims, including one minor, were rescued from trafficking situations, the department said.

The suspects were not part of a single sex-trafficking ring, said Jill Oliveira, a spokeswoman for the Bureau of Criminal Apprehension with the Department of Public Safety.

“These were separate instances where they either responded to undercover officers posing as sex buyers or undercover officers posing as minors,” Oliveira said in a phone interview.

The sting operation occurred as ten of thousands of fans converged on Minneapolis for the semifinals and final of the National Collegiate Athletic Association’s men’s basketball championship, won this year by the University of Virginia.

Some 47 people face felony charges of solicitation of a minor or solicitation of prostitution with someone under 16 years of age. Another 11 were booked on probable cause of sex trafficking and promotion of prostitution, the agency said.

“This operation is an example of the aggressive steps necessary to stop traffickers and johns who buy and sell people for sex in our communities,” said Drew Evans, superintendent of the Bureau of Criminal Apprehension.

It involved more than 33 local and state agencies along with Homeland Security Investigations, a unit of the U.S. Department of Homeland Security.

Most of the suspects were from the greater Twin Cities area, the state department of public safety said, referring to Minneapolis and Saint Paul.

Authorities routinely conduct sting operations coinciding with large U.S. sporting events. During the week leading up to this year’s Super Bowl in Atlanta, authorities arrested 169 people in a sex-trafficking sting.

The Minnesota sting comes less than two months after New England Patriots owner Robert Kraft was charged with soliciting sex as part of an investigation into sex trafficking at several Florida day spas. Kraft, who has pleaded not guilty, was one of 25 men who were taken into custody in the sting.

More than 5,100 cases of human trafficking were reported to the National Human Trafficking Hotline in 2018. That amounted to 40 percent fewer cases than the 8,500 reported in 2017, which was a five-year high, the organization said.