The two missing sailors are crew members on the destroyer USS Peterson, seen in this file photo.

WASHINGTON (CNN) -- U.S. Navy rescuers scoured the Persian Gulf on Sunday for two sailors missing after a ship allegedly smuggling Iraqi oil sank with them aboard, a U.S. Navy spokeswoman said.

Three members of the suspect vessel -- a merchant ship sailing under a United Arab Emirates flag -- were also missing and one was dead, said Lt. Melissa Schuermann, public affairs officer for the U.S. Navy 5th fleet.

Schuermann said the destroyer USS Peterson, part of the Operation Northern-Southern Watch mission set up to keep an eye on ships sailing in and out of Iraq, spotted the ship, the Samra, in the Persian Gulf early Sunday morning.

Noticing the ship sitting low in the water and listing, the crew suspected the Samra was carrying smuggled Iraqi oil.

An eight-person security detail boarded the Samra, Schuermann said, and found 1,700 tons of Iraqi oil aboard. It was not clear exactly when the ship began to sink or how long the Americans had been aboard.

Schuermann also could not comment on what part of the ship the U.S. sailors were when the Samra sank, saying an inquiry was under way.

U.S. officials said they did not consider the sinking an attack on U.S. personnel and the Peterson did not fire on the Samra.

"There was no incident, no hostile incident at sea, but rather, when American sailors boarded to check out the cargo, the ship sank," National Security Adviser Condoleezza Rice said on CNN's Late Edition. "It may have been weather-related, it may have been overloaded, but we have no reason to believe it was a hostile incident of any kind."

Six of the Peterson crew and 10 members of the Samra crew were rescued from the waters after the Samra sank, Schuermann said.

The Navy spokeswoman said the Navy frigate USS Ingraham, the cruiser USS Leyte Gulf and two helicopter squadrons from the 5th Fleet in Bahrain had joined the Peterson to search for the missing sailors. The fleet support ship USNS Catawba and the Australian frigate HMAS Sydney were also on hand, she said.

Operation Northern-Southern Watch has diverted 99 ships this year, Schuermann said. Most are taken to a country that agrees to accept the ship for processing, she said, and the result could be a seizure of the cargo and/or fines.

Some ships, she said, are ordered back to Iraq because of seaworthiness or environmental concerns. Schuermann said she didn't know if any oil was leaking from the Samra.

The sailors were identified as Petty Officer First Class Vincent Parker, 38, of Preston, Mississippi, and Petty Officer Third Class Benjamin Johnson, 21, of Rochester, New York.

Parker has been in the Navy since 1982, and Johnson enlisted in 1998.

CNN Freelance Writer Jeff Levine contributed to this report.