The death toll from the crash of a Greek F-16 at a Spanish military base during an elite NATO pilot training program rose to 11 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 Tuesday, the ministry said in a statement.

Eleven Italians and nine French were injured. Three of the French and one Italian being treated for severe burns at a Madrid hospital and the rest had been treated and released, the ministry said.

Three French jets and two Italian jets were damaged and French Defense Minister Jean-Yves Le Drian was traveling to Madrid Tuesday.

The Greek F-16 and the military personnel gathered at the base were taking part in an annual training exercise called the Tactical Leadership Program.

Competition among experienced pilots to be selected is fierce for the one-month training program to advance their tactical capabilities 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. None of the American, British, German and Spanish military members present were injured, the defense ministry said.

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.