LA RIOJA, Argentina (AP) — Organizers say that a Polish motorcyclist competing in the Dakar Rally has died of unknown causes.

Dakar said in a special bulletin on its website Tuesday that Michal Hernik, 39, died during the third stage of the race between San Juan and Chilecito, Argentina.

Hernik showed no signs of an accident and the circumstances of his death have not yet been determined. His death is the first in this year's Dakar rally.

When Hernik's tracking signal was lost, a search began for the rider at 3:23 p.m. local time (1823 GMT), according to the statement. An ambulance helicopter found the rider about 300 meters from the route about 30 minutes later.

It was Hernik's first time participating in the race.