The US Air Force said the F-15C Eagle went down after taking off from the RAF Lakenheath base near the town of Mildenhall in eastern England.

The base is home to the 48th Fighter Wing, which has operated from there since 1960 and has more than 4,500 active-duty military members.

"A US Air Force F-15C Eagle crashed at approximately 0940 (0840 GMT) today (Monday) in the North Sea," said USAF Captain Miranda T. Simmons, from RAF Lakenheath.

"The cause of the crash as well as the status of the pilot are unknown at this time, and UK Search and Rescue have been called to support."

The Maritime and Coastguard Agency said it was coordinating the response.

"The HM Coastguard helicopter from Humberside has been sent along with Bridlington and Scarborough RNLI (Royal National Lifeboat Institution) lifeboats," it said in a statement.

"Following a Mayday broadcast by HM Coastguard, other vessels nearby are heading to the area," it said, adding that the plane went down 74 nautical miles (137 kilometres) off the East Yorkshire coast.

Citing a flight tracker website, Sky News television said the plane circled in the area before disappearing.

Manufactured by Boeing, the single-seater F-15C entered US Air Force service in 1979, according to Janes security and defence group.

A total of 211 of the 409 aircraft produced are in service today.

Royal Air Force spokesman Martin Tinworth said the aircraft has an "exceptional flight safety record".

A US F-18 fighter jet crashed near the town of Ely, in eastern England, in October 2015, killing the pilot, after taking off from RAF Lakenheath.

The previous October, an F-15 aircraft from the base crashed into a field but the pilot ejected safely. In January that year, four airmen were killed when a US helicopter crashed during a low-flying training exercise.

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