Hungarian soldiers had been taking part in a training mission when the accident happened.
ADVERTISEMENTAt least two Hungarian soldiers have died and a third has been reported missing after a military helicopter crashed into a canyon in a mountainous region of Croatia.
Josip Brozicevic, head of the Croatian mountain rescue service, said the wreckage of the aircraft had been found in the canyon of the Cikola river, near Drnis, some 50km from the Adriatic coast.
"The bodies of two crew members have also been found," he said. "The search is under way for the third crew member".
The Hungarian Ministry of Defence confirmed the incident, adding that two helicopters were taking part in a training mission when one of the aircraft crashed "under unknown circumstances".
"The Hungarian Ministry of Defence immediately began informing the families," said a statement.
The Croatian defence ministry said it had mobilised a plane and a helicopter to help in the search.
Croatia's Defence Minister Mario Banozic expressed his condolences over the death of the Hungarian Air Force members who “invested their knowledge and abilities to contribute together with their countrymen to our joint security.”
“This tragic event in challenging times, in which we witness the most serious threat to global security in decades, reminds us of the importance of solidarity and compassion,” said Banozic.
The footage aired by Croatia's state HRT television showed rescue teams accessing a steep, rocky terrain of the canyon zone. The report said that a witness called the emergency services around noon after seeing smoke rising from the site.
Croatia joined Nato in 2009 and often hosts military exercises with its Alliance partners.