HONOLULU -- The remains of what are believed to be 24 American servicemen killed on a Pacific island during World War II have been returned to the U.S. for identification.

The Pentagon says a U.S. military aircraft carrying flag-draped coffins arrived this week at Hawaii's Joint Base Pearl Harbor-Hickam.

History Flight, a Florida-based nonprofit group, says its members discovered the remains during excavations on Tarawa, in the Gilbert Islands.

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Nearly 1,000 Marines and 30 sailors were killed during the assault on the Japanese-held atoll in November 1943.

After the war, the military was unable to locate the remains of over 500 servicemen buried there and declared them "unrecoverable" in 1949, according to History Flight.

The group recovered the remains of 35 Marines in 2015. The group says the two recoveries are some of the largest for U.S. battlefield remains since the Korean War.

The latest group of remains will be examined at a forensic laboratory on Oahu.