Two triathletes from Mexico and Great Britain have been confirmed dead, after collapsing during the world championships in Spain.

"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," said World Triathlon, 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."

The Mexican Triathlon Federation named Roger Mas Clomber, 79, as one of those deceased, but the British national body has not named its athlete.

No cause of death has been given for either triathlete competing in the age-group division over 750m swim, 20km cycle and 5km run.

More than 5500 athletes are participating in the championships, which began with the U23 races and conclude with the elite events on Monday (NZ time).

New Zealand's Dylan McCullough finished eighth among the U23 men, while Brea Roderick placed 14th in the U23 women. Olympic silver medallist Hayden Wilde is among the favourites for the elite men's race.