The U.S. Navy says results of an internal investigation into how 10 American sailors entered Iranian territorial waters have been handed over to the commander overseeing the region for review.

Cmdr. Kevin Stephens, a spokesman for the U.S. Navy's 5th Fleet, said on Wednesday that fleet commander Vice Adm. Kevin Donegan received the findings on Sunday.

Stephens says that Donegan can endorse the report as is, add to or revise it, or call for further investigation within 30 days.

The sailors were detained while transferring their two small armed boats from Kuwait to Bahrain in January near Iran's Farsi Island, which is in the middle of the Persian Gulf.

They were released unharmed less than a day later, but details of how they ended up in Iranian hands remain unclear.