Four Italian members of the European Union Force in Bosnia (EUFOR) were killed and 11 others injured on Thursday when an Italian military helicopter conducting a training operation crashed.
EUFOR said the Chinook CH-47 helicopter crashed while on a "routine mission" in the Brcko region, about 180 kilometres (110 miles) north of Sarajevo.
"There were a total of 15 people on board the helicopter. Three people died in the crash," Salih Ibrahimbegovic,
spokesman for Brcko hospital, told media.
"Twelve people were transported to our hospital. Unfortunately, a fourth person succumbed to injuries in the hospital," Ibrahimbegovic added. The Italian defence ministry said the victims were two soldiers and two Red Cross volunteers.
"In this time of profound grief, my first thoughts go to the families of our fallen soldiers, to whom I extend my personal condolences," Italian Defence Minister Guido Crosetto said.