A U.S. fighter jet has crashed into the sea off the Japanese island of Okinawa.
A US Air Force's F-15 aircraft takes off at Kadena US Air Force Base on Japan's southwestern island of Okinawa on June 16, 2009.
Almost 18,000 Americans and more than 4,000 work on Kadena Air Base, which is home to the 18th Wing and associated US Air Force units.
However, Kadena airbase later posted on Twitter that the pilot is in a serious condition.
"Our hearts and prayers go to the pilot and his family as they go through this hard time", a post said.
"I sincerely appreciate the strong support of our Japanese partners in this hard situation", he said in an 18th Wing statement issued Monday evening.
The incident happened at about 6:36 a.m. local time during a routine training mission.
"Kadina has temporarily paused F-15 local training operations while the 18th wing reviews operational, maintenance and safety procedures with unit personnel", the release said.
The incident was the second crash involving a US-made aircraft in the region in the span of one week.
Takeshi Onaga, governor for Okinawa, has called on the USA military to suspend flights of F-15 jets until the aircraft are declared safe.
Okinawa government officials asked the US military to suspend F-15 flights until their safety could be confirmed, Kyodo reported.
"Huge thank you to the Japan Air Self-Defense Force search and rescue team out of Naha Air Base this morning". One was a window that fell onto the sports field of an elementary school from a US heavy-lift helicopter; the other was a plastic part that fell onto a day care facility and was believed to have come from a USA helicopter. Particularly, in January, two USA attack helicopters from Marine Corps Air Station Futenma made emergency landings in the Okinawa prefecture in two separate incidents, prompting public concerns. No one was injured in the accident.