Two athletes died while participating at the World Triathlon Championships in Spain on Thursday, the sport’s governing body has confirmed.

Both competitors – one from Mexico and one from Great Britain – were participating in the sprint category on the first day of competition at the Torremolinos-Andalucia Triathlon Championship Finals.

“It is with deep sadness that we can inform that two participants (one from Mexico; one from Great Britain) have died at the World Triathlon Torremolinos-Andalucía AG Sprint Distance World Championships, taking place today, October 17,” World Triathlon said in a statement. “Our deepest condolences go to their respective family, friends, National Federations and all the triathlon family.

“World Triathlon, the Spanish Federation and the LOC are in contact with their families and NFs (national federations) to provide all the support needed in these difficult and sad times.”

CNN has reached out to event organizers for comment.

The Mexican Triathlon Federation confirmed the identity of one of the athletes as 79-year-old Roger Mas Colomber.

“It is with deep sadness that we report the death of Mexican triathlete Roger Mas Colomer, aged 79, during his participation in the Triathlon World Championship on the afternoon of Thursday, October 17, in Torremolinos, Spain,” it said in a statement posted to X, formerly known as Twitter.

“We deeply regret this event and share the grief of his family and friends.”

British Triathlon also confirmed the death of a member of its Age-Group team but did not name the athlete.

“British Triathlon can confirm that one of our Age-Group Team has sadly passed away whilst competing at the World Championships in Torremolinos, Spain,” it said in a statement.

“Their family have been notified and we are supporting them at this time. British Triathlon and the Age-Group Team send their condolences and we request that their privacy be respected at this time.”

No cause of death was given for either competitor.

The Age-Group category refers to non-professional triathletes who compete against other non-pros within a five-year age band. Age-Group competitors receive the title of “World Triathlete.”

Each Age-Group race featured a 750m (around 0.47 miles) swim, a 20km (just over 12.4 miles) cycle and a 5km (3.1 miles) run.

The World Triathlon Championships are being hosted in the municipality of Torremolinos in southern Spain. More than 5,500 athletes are competing, with over 4,000 of those being Age-Group racers. Seventy-nine countries are being represented across the championships.

The championships began on Thursday with the Under-23 Finals and will conclude on Sunday with the Elite Men’s Finals. (CNN)