"At this stage, we can say that one out of two helicopters was downed. We have two martyrs," Yildirim said in televised remarks, but said there was: "no evidence (yet) in our hands to prove that it was a result of outside intervention."

Earlier Turkish President Recep Tayyip Erdogan said a military helicopter had been "shot down" over an area which Turkish media identified as the southern border province of Hatay.