Pro sports leagues warn players about organized crime after Patrick Mahomes, Travis Kelce's homes were broken into. Here’s what we know.

A recent string of high-profile burglaries targeting the homes of professional athletes, like Kansas City Chiefs players Patrick Mahomes and Travis Kelce, have prompted the NFL and NBA to issue security memos to its teams and players, urging them to take additional steps to secure their homes and valuables.

The thieves appear to be taking advantage of the timing of the star athletes’ game schedules, according to the NFL memo.

The memos detail how the burglars have gathered intel on potential victims and offer recommendations on how players can prevent themselves from becoming victims of burglary in the future.

The FBI is investigating whether the burglaries are connected to a transnational crime ring, according to an NBC News report.

While there have been no public reports of NHL players being targeted by burglaries, the league has also warned its players about security threats to the homes of professional athletes, CNN reported.

Here’s what we know:

Which players have been victims of the recent string of burglaries?

• Sept. 15: Minnesota Timberwolves guard Mike Conley Jr.’s home was broken into while he was at a Minnesota Vikings game, and jewelry was stolen.

• Nov. 2: The home of Milwaukee Bucks forward Bobby Portis was broken into while he was playing a game against the Cleveland Cavaliers. He has offered a $40,000 reward for information that leads to the return of his belongings after he put out a plea on social media saying the thieves took “most of my prized possessions.”

• Oct. 6: Local police were called to Mahomes’s house after a break-in was reported by a member of his security team the night before an Oct. 7 home game. “It's disappointing. I can't get into too many details because the investigation is still ongoing,” Mahomes said during a Nov. 13 press conference.

• Oct. 7: A thief broke into Kelce’s home while he was playing against the New Orleans Saints. Police had confirmed that $20,000 in cash was stolen but did not previously disclose a stolen watch that has now been recovered in Providence, R.I.

What do the security memos say?

The NFL’s memo stated: “The homes of professional athletes across multiple sports leagues have become increasingly targeted for burglaries by organized and skilled groups. Law enforcement officials have noted these groups appear to exploit team schedules to target athletes’ homes on game days.” It did not provide details about the suspected group’s identity.

The memo noted ways in which the burglary groups appear to be conducting extensive surveillance by gathering information on their targets through “public records, media reports and social media.” Some thieves are reportedly posing as delivery drivers, groundskeepers and neighborhood joggers to gather intel. Burglars are also entering players’ homes by entering side doors via balconies and second-story windows, or by scaling walls.

The NFL advises players to use caution when using social media, advising them not to post their activities as they happen, and not to share photos of valuable objects like jewelry or clothing.

The NBA, which issued a similar security memo, relayed information from the FBI that revealed some burglaries are linked to “transnational South American Theft Groups” it described as “reportedly well-organized, sophisticated rings that incorporate advanced techniques and technologies, including pre-surveillance, drones, and signal jamming devices.”

The memo also said the thieves are targeting goods that can “be resold on the black market, such as jewelry, watches, and luxury bags.”

Both memos advise players to take the following home security steps, including updating alarm systems and activating them when not at home, testing those systems regularly, using dogs for home protection and vetting contractors doing work in and around homes.