Mexican rescuers spotted "no survivors" while surveilling a crash site of a private plane in the north of the country, authorities said on Monday.
The wreckage is believed to be the Bombardier Challenger 601 jet that disappeared from radar while flying from Las Vegas to the north Mexican city of Monterrey with at least 13 people on board.
An air search of the isolated area found a wreck matching the private jet.
"Everything indicates it is the plane" that went missing, said Miguel Villarreal, head of the Monclova International Airport in the state of Coahuila.
"The flight plan reported there were 11 passengers on board, plus the crew," he told local TV station Multimedios. Some outlets put the total number of people on board to 14.
Passengers on the private jet had reportedly visited Las Vegas to see Mexican boxer Saul "Canelo" Alvarez fight American Daniel Jacobs for the middleweight title fight on Saturday. Alvarez won the fight.
The boxer posted his condolences on Twitter, saying "I deeply lament the terrible accident of the plane coming from Vegas. I'm deeply grateful for the support of all the people who travel to see my fights. My prayers are with their families."