An American cargo ship under contract to the U.S. Navy fired warning shots at a small Egyptian boat while passing through the Suez Canal, the U.S. military said Tuesday. Egyptian authorities said at least one man was killed, but the U.S. said an investigation was under way and it had no reports of casualties.

The Global Patriot, which was under short-term charter to the Navy's Military Sealift Command, entered the canal from the Red Sea at Suez after dark Monday when it was approached by several small boats, according to U.S. and Egyptian officials.

The U.S. Navy has been careful about the activities of small boats near their warships since the 2000 suicide attack by an explosives-packed motor boat on the USS Cole in Yemen killed 17 sailors.

A U.S. Navy security team aboard the Global Patriot fired the warning shots, said Lt. Nathan Christensen, deputy spokesman for the U.S. 5th Fleet, based in Bahrain.

"The boats were hailed and warned by a native Arabic speaker using a bullhorn to warn them to turn away. A warning flare was then fired," said a statement from the U.S. Embassy in Cairo. "One small boat continued to approach the ship and received two sets of warning shots 20-30 yards in front of the bow."

The statement added that "all shots were accounted for as they entered the water." It also said that "initial reports indicate that no casualties were sustained on either vessel."

The New York-based company that owns Global Patriot also said the reports they received indicated there were no injuries or casualties during the incident.

"The reports we have from the ship command were that there were some flares fired at the approaching small boats and ... there were no injuries or casualties to anyone whatsoever," said Hormoz Shayegan, vice president of Global Container Lines Limited. He said the crew of the vessel was unarmed.

An Egyptian security official at the canal, however, said that after the warning shots, a man was shot dead in the small boat and that the three other men with him were wounded.

The body of the man, Mohammed Fouad, was taken to a hospital morgue, then transferred to the Ibrahim Nafie mosque ahead of burial, the head of the union of seamen in Suez, Abbas al-Amrikani, told The Associated Press.

We are praying over his the body right now," al-Amrikani said by phone over audible sounds of prayer. "I saw the body. The bullet entered his heart and went out the other side." He added that Fouad was 27 years old.

The Egyptian government had no immediate comment. The state news agency MENA reported an Egyptian was killed "when an American ship opened fire."

Small boats selling cigarettes and other products often swarm civilian ships moving through the canal. The merchants know not to approach military vessels, but the Global Patriot looked like a civilian vessel, said the security official, speaking on condition of anonymity because he was not authorized to speak to the media.

"We are very conscious of being in heavily trafficked areas and we as professional mariners try to keep people from getting too close," 5th Fleet spokeswoman Cmdr. Lydia Robertson told The Associated Press by phone from Bahrain. "Our team did take the appropriate steps to take those measured steps to warn the vessels that were getting too close."

Robertson said the same rules of engagement applied for warships as for those under contract.

In Washington, the State Department said Washington took the issue seriously and would work with Egypt to prevent similar incidents. Spokesman Sean McCormack said he expected Secretary of State Condoleezza Rice and Egyptian Defense Minister Mohamed Hussein Tantawi would touch on the matter at the State Department later Tuesday in a private meeting that is likely to focus on the security situation in the Gaza Strip. Tantawi also was to meet with Defense Secretary Robert Gates on Tuesday.

Egyptian officials said the ship was continuing its journey through the canal and was expected to arrive at Port Said near the Mediterranean by nightfall.

The Global Patriot is registered to the New York-based Global Container Lines and, according to the company Web site, the vessel trades between the United States, the Red Sea, the Persian Gulf and East Africa.

Some 7.5 percent of world sea trade passes through the canal, which at its narrowest is 120 yards wide. The canal is a major source of foreign currency for Egypt.