Untrained [Somali] teenagers with heavy weapons ... Everybody in the room knows the consequences of that.
The US-flagged Maersk freighter seized four days ago by Somali pirates docked safely Saturday in Mombasa, but its American crew will remain aboard while the FBIinvestigates, Maersk Line's president said.
"Because of the pirate attack, the FBI has informed us this ship is a crime scene," John Reinhart told a press briefing in the US state of Virginia.
"Therefore, the crew members will have to stay on board" the Maersk Alabama, which was carrying US food aid to Africa when it was set upon by pirates who have taken the captain hostage.
Richard Phillips is being held by the pirates who were forced off the vessel shortly after seizing it early on Wednesday while it was in the Indian Ocean about 500 kilometres (310 miles) off the Somali coast.
The crew managed to regain control of the ship, but the pirates fled in a lifeboat taking Phillips hostage.
Phillips jumped into the water overnight Thursday to Friday and tried to swim to the USS Bainbridge warship, but pirates jumped in and recaptured him, US military officials said.
The lifeboat is now adrift in the Gulf of Aden under close observation by two US warships.
One of those ships on Saturday sent a small naval party toward the lifeboat in an effort to talk with the four pirates on board, CNN reported from Bahrain, where the US Fifth Fleet is based.
The pirates opened fire on the approaching sailors and the US Navy retreated without further incident to avoid antagonizing the situation any further, CNN said, adding that the lifeboat was now roughly 20 miles (32 kilometers) from the Somali coastline.
The four pirates aboard the lifeboat warned Saturday that using force to free Phillips would end in "disaster."
A pirate captain told AFP by telephone from the northern Somali pirate lair of Eyl that they were preparing to transfer the American captain from the lifeboat to a pirate ship along the Somali coast.
One of the crew of the Maersk Alabama speaking to reporters from the side of the ship talked about their ordeal.
"It was something (terrifying) to encounter the pirates; they were heavily armed," he said, speaking on condition of anonymity.
"The captain is a hero, he saved our lives," another added.
The crew, visibly tried but sporting large grins, then retired inside the ship.
Journalists will not be allowed to board the vessel while the Federal Bureau of Investigation conducts its probe, Reinhart said, adding that he did not know how long that would take.
"They're in control," he said. "It is moved from the rescue to now investigation. After the investigation, we then move to repatriation, which is bringing our heroes (crew members) home."
However, Reinhart said, the case is far from closed.
"When I spoke to the crew, they won't consider it done when they board a plane and come home. They will not consider it done until the captain's back.
"We believe that Captain Phillips will survive this situation.... We appreciate his courage. We know that he will survive because he will never give up," Joseph Murphy, father of the Maersk Alabama's acting captain Shane Murphy, told a press conference in the US state of Massachusetts.
The 20-crew ship was carrying provisions for the UN World Food Programme, including 4,097 tonnes of soya and maize and 990 tonnes of cooking oil for vulnerable populations in Somalia, Uganda and Kenya, an official from the agency told AFP.
The official said the unloading could start on Sunday.