Two American sailors are missing at sea and are the subject of an intense Navy search after the tanker they were on sank Sunday.

Petty Officer 1st Class Vincent Parker, 38, of Preston, Miss., and Petty Officer 3rd Class Benjamin Johnson, 21, of Rochester, N.Y., were in a party of eight U.S. sailors who boarded a United Arab Emirates-flagged tanker in the northern Persian Gulf that the Navy says was carrying illegal Iraqi oil.

The two sailors were identified by a Pentagon official speaking on condition of anonymity.

Tthe tanker sank at about 4:45 a.m. local time Sunday, said Lt. Melissa Schuermann, a spokeswoman for the U.S. Naval Forces Central Command in Bahrain.

The other six Americans were rescued, she said. The U.S. sailors had boarded the tanker from the USS Peterson, a destroyer whose home port is Norfolk, Va.

Schuermann said it was too early to speculate on the reason for the sinking. She described the ship as being in "overall poor condition" and "grossly overweighted."

"We're doing a preliminary inquiry into the facts and circumstances surrounding the incident," she said.

In Washington, Deputy Defense Secretary Paul Wolfowitz indicated that the sinking was an accident.

Condoleezza Rice, President Bush's national security adviser, echoed that statement.

"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," she said.

The entire 14-person crew of the tanker, the Samra, was believed to be Iraqi, Schuermann said. The body of one crew member was recovered and three others were missing, she said.

The U.S. Navy said the tanker was carrying an estimated 1,900 tons of Iraqi oil in violation of U.N. sanctions against Iraq.

Wolfowitz said the tanker had been intercepted as part of a long-running U.S.-led international maritime operation designed to enforce the U.N. oil embargo against Iraq.

"It is as a reminder that at the same time we are conducting a war in Afghanistan we have military [personnel] engaged in Bosnia and in Kosovo and in Iraq and in Korea. The world remains a dangerous place -- not just in Afghanistan," he said on CBS' Face the Nation.

It was not clear whether the Samra was leaking oil after its sinking. The Navy said it was still focusing on search and rescue.

The U.N. imposed sanctions after Iraq's 1990 invasion of Kuwait. They prohibit Iraq from exporting oil without U.N. authorization. This year, the U.S.-led Maritime Interception Force has boarded many ships and diverted 99 vessels while enforcing sanctions.

The search was being conducted with the help of helicopters from the Peterson as well as the USS Ingram, the USS Leyte Gulf and an Australian frigate, the HMAS Sydney, Schuermann said.

The Associated Press contributed to this report.