Four Spanish soldiers and their interpreter were injured Saturday when their armoured vehicle hit an explosive device in Afghanistan, Defence Ministry sources said in Madrid, dpa reported.
The five were on a reconnaissance patrol near Ludina in north-western Badghis province.
Three of the victims suffered serious injuries. Two of them - a lieutenant and a female soldier - each had to have a leg amputated.
The vehicle had been designed to resist explosions. But the shielding was overwhelmed by the large amount of explosives contained in the device, media reported.
Spain has about 1,500 troops in Afghanistan as part of the NATO-led International Security Assistance Force (ISAF).