An accidental blast during training at a Spanish army school near the capital Madrid has killed five soldiers, including top bomb disposal experts.
Three were injured in the explosion at the Hoyo de Manzanares military engineering academy, during training for UN peacekeeping duties in Lebanon.
Some of the victims had just returned from service in Afghanistan, Defence Minister Carme Chacon said.
"They were training to save lives... when they lost their own," she added.
Three sergeants and two corporals were killed in the explosion, which occurred in the grounds of the academy.
Among the dead "were some of the best bomb disposal experts in the armed forces", Ms Chacon told reporters.
Police in Hoyo de Manzanares said the training was being carried out by a group of 16 members of the army and marines.
The academy features an international demining centre.