Washington DC: One crew member of the US Navy helicopter that crashed off the San Diego coast was rescued, while five remain missing, US Navy informed on Wednesday.

The incident happened during routine flight operations some 60 nautical miles off the coast of San Diego at 4:30 pm Pacific Daylight Time (PDT).

"An MH-60S helicopter embarked aboard USS Abraham Lincoln (CVN 72) crashed into the sea while conducting routine flight operations approximately 60 nautical miles off the

coast of San Diego at 4:30 p.m. PDT, Aug. 31. UPDATE (11 p.m. PDT): Currently, one crewmember has been rescued and search efforts continue for five additional crewmembers," US Pacific Fleet said in a statement.

"Search and rescue operations are ongoing with multiple Coast Guard and Navy air and surface assets," it added.

Earlier in the day, the US Pacific Fleet said that a helicopter crashed into the sea while conducting an operation.