The NFL is growing concerned about a possible international crime ring targeting its players.

Following the reports from ABC News and Fox 4 Kansas City that a South American crime ring may be connected to the Oct. 6 and 7 burglaries at Travis Kelces and Patrick Mahomes houses in Kansas City, the NFL has issued a memo regarding player security.

PEOPLE obtained a copy of the memo sent by the NFL to its team security directors and the players union warning about organized criminals targeting the homes of professional athletes.

The memo sent out by the NFL informed recipients of the perpetrators strategy in finding targets and suggested that players utilize increased privacy measures like waiting to post on social media until after theyve left a location and installing advanced security systems.

A source close to the situation told NFL inside Tom Pelissero that the transnational crime ring is legit and been focused on NBA and NFL players over the last three weeks.

And its all over the country, the source added.

As additional information about the suspected crime ring is made public, multiple people close to the situation warned that the perpetrators are using public records to find the addresses of their pro-athlete targets, and conduct extensive surveillance before burglarizing the residence.

The memo also said the burglars are non-confrontational and do not act while the residents are home. Instead, they track the targets social media accounts  and those of their families  as well as team schedules to know when the homes will be empty.

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PEOPLE reached out to the NFL for comment, but did not immediately hear back.

Mahomes eight-acre Belton, Mo. estate was broken into on Oct. 6. When asked about it during a Chiefs press conference, the quarterback said, Obviously, its frustrating, disappointing but I cant get into too many of the details because the investigation is still ongoing.

Mahomes added that it was something you dont want to happen to really anybody.

Kelces Leawood. Mo. residence was broken into on Oct. 7, the day the Chiefs played the New Orleans Saints at Arrowhead Stadium, and police said $20,000 was taken from the tight ends home.

Over in the NBA, Milwaukee Bucks forward Bobby Portis home in River Hills, Wis. was also burglarized similarly.

Portis, 29, revealed on Instagram that many of his prized possessions were taken from his Milwaukee residence during a Nov. 2 home invasion. The NBA champ said the burglary occurred while he was in Ohio for a road game against the Cleveland Cavaliers.