The US Air Force (USAF) F-22 Raptor fighter jets at the 1st Fighter Wing, Joint Base Langley-Eustis, Virginia, US, have resumed flight operations after being grounded.

The fighter jets in the Virginia USAF base were grounded following an oxygen-related problem resembling hypoxia with one of the unit’s pilots.

Defense News has reported the two squadrons of F-22s at the Alaska base have also resumed flight operations.

Air Combat Command spokesman Monica Miller Rodgers said: "We are committed to protecting our fleet of F-22 Raptors and the pilots and maintainers who enable its combat capabilities."

The Air Force lifted the ban even while the problem with the F-22’s oxygen system is still being investigated.