The hijacked U.S. ship freed by its crew is sailing towards the Kenyan port city of Mombasa where it's due on Sunday, a regional maritime official said on Friday.

But Captain Richard Phillips, who was snatched by the hijackers in the struggle, was still held on a lifeboat the attackers took from Maersk Alabama.

Andrew Mwangura, East Africa's Coordinator of Seafarers Assistance Program (SAP) said the Maersk Alabama cargo ship said is sailing to Mombasa under armed guard.

"The Maersk Alabama is expected dock at the port of Mombasa either on Saturday evening or early Sunday," Mwangura told Xinhua by telephone.

The pirates are holding Captain Phillips hostage in a lifeboat around 300 miles east of the Somali capital, Mogadishu.

They attacked his freighter as it carried food aid for Somalia and Uganda to Mombasa in Kenya.

The crew of 20 Americans managed to retake control of the Danish-operated vessel and have been trying to negotiate their captain's release. "We are not afraid of the Americans," one of the pirates reportedly told reporters by satellite phone.

Maritime officials have said negotiations could be lengthy, with the pirates likely to want a hefty ransom for the captain as well as compensation for a boat that was wrecked in the attack.

The cargo ship, carrying food aid destined for Somalia and Uganda, was taken about 500 km off Somalia's coast in the early hours of Wednesday.

Reports say the ship's lifeboat has run out of fuel, other pirates are too nervous to help them due to the presence of foreign naval ships, and the USS Bainbridge destroyer is up close.

The head of the US Central Command, Gen. David Petraeus, said more ships would be sent to the area to ensure that there is capability that might be needed over the course of the coming days. Washington says it was seeking a peaceful solution, but was not ruling out any option in freeing Phillips.

Some political observers believe the additional ships are a show of force in response to a rise in the number of attacks and the first one on a U.S.-flagged ship. The move is expected to give the U.S. military more eyes on the threatened area to act as a deterrent to future pirates attacks.

A spokesman for the Maersk Alabama cargo ship Kevin Speers said the USS Bainbridge, part of a coalition naval force sent to combat piracy in the region, arrived early Thursday morning and had made contact with the lifeboat.

Somali pirates have stepped up their attacks in recent weeks after a brief lull. The Maersk Alabama was the sixth ship to have been seized since Saturday.

The Kenyan port city of Mombasa, south of the Somalia coast, is a vital hub for receiving food assistance for Sudan, Uganda, Rwanda, Somalia and Kenya.

Pirates typically hold the ships and crews until large ransoms are paid by the shipping companies. The attacks are threatening to destabilize one of the world's busiest shipping lanes.

(Xinhua News Agency April 10, 2009)