Five US Navy crew members are missing after their helicopter crashed into the Red Sea around noon local time on Sunday, a statement from US Naval Forces Central Command said.
It was not clear what caused the MH-60S Knighthawk helicopter to crash during routine operations.
"The status of the five personnel on board the helicopter is still being determined," the statement said. "The crash was not due to any sort of hostile activity."
The helicopter was assigned to Helicopter Sea Combat Squadron 6 — nicknamed the HSC Indians — at the time of the crash.
According to Navy officials, the Knighthawk was either trying to land or take off from the guided-missile destroyer, the USS William P. Lawrence.
The search for the helicopter's five crew members is being carried out by small boats and aircraft stationed on the aircraft carrier USS Nimitz.
The USS Nimitz was moved into the region in early September in anticipation of a possible missile strike against Syria.
The nuclear-powered aircraft carrier joined the Princeton, a cruiser, and three destroyers - the William P. Lawrence, Stockdale and Shoup, in the Red Sea, reports Reuters.
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