PHOENIX, Sept 5 (Reuters) - An Air National Guard F-16 Fighting Falcon jet crashed in southeastern Arizona on Tuesday with the fate of the pilot unknown, Arizona Air National Guard officials said.
Rescue efforts were under way after the fighter jet crashed at about 3 p.m. mountain time (5 p.m. EDT) some 20 miles northwest of the city of Safford, the Air National Guard said in a statement.
The crash occurred during training exercises out of Tucson International Airport, the Guard said.
An interim safety board has been assembled by the U.S. Air Force to investigate the incident.
(Reporting by David Schwartz; Editing by Dan Whitcomb and Sandra Maler)