A French serviceman died Tuesday morning of injuries sustained one day earlier when a Greek F-16 fighter jet crashed while taking part in a NATO training exercise in Spain, the French defense ministry said, bringing the crash's death toll to 11. Another 20 people were injured in the crash, which local media reported was the result of an “incorrect maneuver” made by the Greek pilots. The Spanish defense ministry said that the jet “lost power” after taking off from the runway at Llanos airbase outside Albacete, Spain, and quickly crashed around 1,000 feet from the runway.

The French national was badly burned in the accident, according to BBC. Eleven Italian and nine French service-members were hurt, while the two Greek pilots and nine total French individuals were killed. Five other jets and “numerous” helicopters were damaged, according to the Italian defense ministry. The Greek defense ministry declared three days of mourning on Monday, and French Defense Minister Jean-Yves Le Drian was headed to the airbase on Tuesday to assess the situation, according to the Associated Press. Video shot soon after the jet crashed into a number of parked jets showed a large plume of black smoke and airbase firefighters responding to the scene. Video can be seen via the Telegraph.

The foreign airmen were training in the Tactical Leadership Program, which is attended by 10 NATO nations as a way to develop the leadership skills of their servicemembers. Belgian, British, Danish, French, German, Greek, Italian, Dutch, Spanish and American personnel are all part of the program, which was founded in 1978.

NATO has enhanced its training regimen over the last several months in response to what the alliance calls Russian aggression in Ukraine. Ukraine is not a NATO member, but the renewed tension with Russia jump-started the alliance, which was formed following World War II to curb Soviet military action. Llanos airbase has been the home of the Tactical Leadership Program since 2009.