NAIROBI, Kenya – The crew on a hijacked Ukrainian cargo ship laden with tanks and heavy weaponry appear to be in good health, a U.S. Navy spokeswoman said Monday.

Lt. Stephanie Murdock, a 5th Fleet spokeswoman in Bahrain, said American officials are in regular contact with the master of the MV Faina, which was seized by pirates off the coast of Somalia late last month with 21 crew on board.

Officials in Moscow say the ship's Russian captain died of a heart condition soon after the hijacking nearly two weeks ago.

The remaining crew appeared fine in a photograph taken Friday, when the pirates granted a request by the U.S. Navy to have the crew step out onto the deck. The picture, released by the Navy, shows the men, mostly expressionless, with gunmen nearby. The crew of Ukrainians, Latvians and Russians are leaning against the railing of the ship but not looking directly at the camera.

“From all indications, everything is fine with the crew members on board,” Murdock told The Associated Press.

Six U.S. warships are surrounding the Faina and a Russian frigate is headed toward the standoff. The Navy warships have been tracking the seized ship amid fears that its weapons might fall into the hands of al-Qaeda-linked Islamic insurgents in Somalia. U.S. officials and others have said the weapons shipment was headed to South Sudan.

In Kenya, a parliamentary committee launched an investigation Monday into whether the arms shipment was headed to South Sudan, not Kenya as the government here has claimed.

The Faina's hijacking, the most high-profile this year, illustrates the ability of a handful of pirates from a failed state to menace a key international shipping lane despite the deployment of warships by global powers. Some 26 ships have been hijacked off the notorious Somali coast this year already.

Moscow has called for naval forces gathering in the area to coordinate their efforts against piracy.

The Somali government has given foreign powers the freedom to use force against the pirates, raising the stakes significantly. Russia, whose warship is not expected for several days, has used commando tactics to end several hostage situations on its own soil, but hundreds of hostages have died in those efforts.

A pirate spokesman, who could not be reached Monday, told the AP via satellite phone last week that the pirates were prepared to defend the ship and would not take less than their stated ransom of $20 million.

The allegation that Kenya would allow weaponry bound for South Sudan to transit through its ports is highly embarrassing for the government, which brokered Sudan's north-south peace deal in 2005.

South Sudan is due to have a referendum on independence in 2011. Many analysts believe the north will be reluctant to let the oil-rich south break away, risking a return to the civil war that has already claimed 2 million lives.

Adan Keynan, chairman of Kenya's Defense and Foreign Relations parliamentary committee, said Kenya should not be seen as helping South Sudan stockpile weapons.

“Kenya should be last country to be seen as taking side on this,” he said.

Last week, Kenya arrested a maritime watchdog official, Andrew Mwangura, who was the first person to say publicly that the tanks and weapons aboard the hijacked ship were headed for Sudan. Police did not say what laws Mwangura was suspected of breaking.

Roger Middleton, an expert on East Africa at Chatham House think tank in London, said the standoff could drag on.

“Ships have been held for two months or more so I think we've got a way to go here,” he said. “They are in a strong bargaining position.”

But, he added, “if they start to think the U.S. or Russia will attack then, they will get nervous.”

AP Writer Meera Selva contributed to this report from London.