MOGADISHU

Military helicopters flew over Somali pirate lairs and battleships stalked a boat on Sunday in which gunmen were holding an American hostage in a five-day high seas standoff.

Armed with assault rifles and a grenade launcher, four pirates and their captive, 53-year-old US ship captain Richard Phillips, were drifting towards land on a lifeboat out of fuel.

Three US warships were watching the situation.

"The captain must be tied to the lifeboat because he tried to escape once," Aweys Ali Said, chairman of the pirate-infested central Somali region of Galkayo, told Reuters.

Pirate sources said US helicopters were dropping supplies for the boat. Phillips is the first American taken captive by Somali pirate gangs who have marauded in the busy Gulf of Aden and Indian Ocean shipping lanes for years.

"The Americans give them food and water -- helicopters drop them on the lifeboat," a pirate from Hobyo village, who identified himself as Hussein, told Reuters.

US officials are anxious to end the standoff, which has gripped Americans since Wednesday when Phillips -- a saxophone-playing, sports-loving father-of-two who lives in rural Vermont -- was taken hostage.

They fear the pirates may try to escape with him if they reach the shore of the Horn of Africa nation, where 18 years of civil conflict has fuelled piracy offshore.

The US-flagged Maersk Alabama container ship was attacked far out in the Indian Ocean on Wednesday, but its 20 American crew apparently fought off the pirates and regained control.

Relatives said Phillips volunteered to go with the pirates in a Maersk Alabama lifeboat in exchange for the crew.

"The captain is a hero," one crew member shouted from the 17,000-ton ship as it docked in Kenya's Mombasa port under darkness on Saturday. "He saved our lives by giving himself up."    

Experts had expected a quick end to the standoff, but the pirates are holding out for both a ransom and safe passage home. Friends told Reuters the gang wants $2 million.

Somali elders, who wield big sway their clan-based society and often negotiate solutions to kidnaps, say they have sent a mediator to sea with the aim of securing safe passage for Phillips' release, and no ransom.

The saga has thrown world attention on the long-running piracy phenomenon off Somalia that has hiked shipping insurance costs and disrupted international trade.

Phillips is just one of about 260 hostages -- the majority, 92, Filipino -- being held by pirates who have targetted vessels from oil tankers to luxury yachts.  They hold about 17 vessels, six taken in the last week.

US officials said the lifeboat had drifted to within 20 miles of the Somali coast but pirate sources and a regional maritime group said it was still much further out. The state of negotiations was unclear, with US officials tight-lipped and the pirates on the lifeboat shouting abuse at journalists who call their satellite phone.

Military officials said the pirates fired on a US craft that approached them from the USS Bainbridge on Saturday. No one was hurt and the craft withdrew.

Helicopters, probably from the nearby US or other foreign warships, also flew over a coastal area used by pirates on Sunday. It was unclear if the two choppers were sent to intimidate the gangs or as some step in a mediation process.

Residents said they could see white soldiers on one of the helicopters which flew over for around half an hour in the area of Haradheere port. One briefly landed.

Resident Ahmed Haji Abdi said people were afraid of being bombed. "We thought there would be air raids this morning. Haradheere is full of pirates," he said.

The standoff has forced US President Barack Obama to focus on a place most Americans would rather forget.

A US intervention in Somalia in the early 1990s was a disast