Seoul, South Korea - A US F-16 fighter jet crashed Monday in South Korea during a routine training exercise after experiencing "an in-flight emergency," the Air Force said, adding the pilot had been rescued.

The incident involving an F-16 Fighting Falcon assigned to the 8th Fighter Wing happened early Monday over the Yellow Sea, a USAF statement said.

"The pilot ejected the aircraft. The pilot has been recovered by Republic of Korea Maritime Forces, awake and in stable condition," it explained, adding there would be further evaluations back at base.

"We are grateful for the safe recovery of our Airman by our ROK Allies and that the pilot is in good condition," said Colonel Matthew C. Gaetke, the 8th fighter wing's commander, according to the statement.

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The USAF said that the cause of the in-flight emergency was unknown.

"The incident will be thoroughly investigated," it said, adding that the name of the pilot and more details about his condition would not be released.

South Korea's defense ministry declined to comment.

In May, a US F-16 jet crashed during a routine training exercise in a farming area south of Seoul. The pilot ejected safely and the accident caused no other casualties.

The US stations some 28,500 troops in South Korea amid tensions with its nuclear-armed neighbor in the north.

In Japan, the US military announced last week that it was grounding its fleet of V-22 Osprey tilt-rotor aircraft following a deadly crash that killed eight airmen.