Approximately 11,000 runners at this year’s Mexico City Marathon have been disqualified after being found to have cut the course at some point during the 26.2-mile race, according to Spanish newspaper Marca.

The disqualified runners represented more than one-third of the 30,000-person field that entered the Aug. 27 race.

Marca reported Monday that the runners were disqualified after missing checkpoints that were placed every 5 kilometers. Some runners allegedly used vehicles or public transport to cut the course.

Race organizers said in a statement to Marca that it will continue to identify and disqualify runners who skipped sections of the race.

“The Mexico City Sports Institute informs that it will proceed to identify those cases in which participants of the XL Mexico City Marathon Telcel 2023 have demonstrated an unsportsmanlike attitude during the event and will invalidate their registration times,” they said.

The Mexico City Marathon has had issues with rampant cheating in the past. In 2017, nearly 6,000 runners were disqualified for similar reasons, with more than 3,000 also being removed from the results the following year.

Bolivian runner Héctor Garibay Flores won the men’s marathon in a course-record 2 hours, 8 minutes, 23 seconds, breaking the previous mark by more than two minutes. Kenyan Celestine Chepchir was the women’s champion in 2:27:17.