WASHINGTON -- U.S. military officials have grounded all F-35 fighter jets while continuing to investigate a runway fire involving one of them at Eglin Air Force Base in Florida.

In a statement issued Thursday, the Pentagon's press secretary said Air Force and Navy officials ordered the F-35 fleet grounded after initial findings in the June 23 incident.

Officials said at the time that the jet caught fire during takeoff. No one was hurt, and the cause remains under investigation.

The Pentagon says that additional inspections of F-35 engines have been ordered, and that the return to flight of the F-35 fleet will be determined based on inspection results and analysis of engineering data.