The death toll from the crash of a Greek F-16 fighter jet at a Spanish military base during an elite NATO pilot training program rose to 11 on Tuesday after one of the French airmen who suffered serious burns died at a Madrid hospital, Spain's defense ministry said.
The death came as Spanish investigators tried to determine what caused the jet to lose thrust as it took off and crash into five parked planes at the Los Llanos air base in southeastern Spain, triggering a series of explosions and a fire that took about an hour to put out.
Two pilots aboard the Greek F-16 were killed along with eight French air force members on the ground and the French airman who died on Tuesday, the ministry said in a statement.
Prime Minister Mariano Rajoy promised his French and Greek counterparts "all the help my government can give in clarifying the facts" of what went wrong.
"Spain and Spaniards always stand with our allies and their pain is ours," Rajoy said.
Twenty French and Italian citizens were injured and four remained hospitalized Tuesday in Madrid undergoing treatment for severe burns, the ministry said.
Three French jets and two Italian jets were damaged. French Defense Minister Jean-Yves Le Drian was traveling to Madrid and the base on Tuesday.
The Greek F-16 and the military personnel at the base were taking part in an annual one-month training exercise called the Tactical Leadership Program.
Competition among experienced pilots to be selected is fierce for the program to advance their tactical ability so they can command large numbers of planes in the air.
The NATO countries who sent personnel to this year's program were Britain, France, Germany, Greece, Italy, Spain and the United States.
Greece's defense ministry on Tuesday announced a three-day period of mourning for its armed forces due to the deaths of the Greek pilots.