An international rescue operation is underway in southern Turkey after an American cave explorer suffered a medical emergency during a descent in the countrys third-deepest cave on Saturday.

Mark Dickey, 40, was with a team roughly 3,400 feet from the entrance of the alpine Morca cave near Anamur when he began suffering from severe gastrointestinal pain and bleeding, rescue officials said.

A rescue team was dispatched the next day and a Hungarian medical unit was able to reach Dickey, who was given a blood transfusion, said the Hungarian Cave Rescue Service , which is assisting in the rescue.