Armed men from different Somali factions are descending on the country's pirate coast, raising fears that a battle is looming over millions of pounds in ransom cash being demanded for the captured supertanker Sirius Star.

Tribal militiamen linked to the pirates, moderate Islamist rebels fighting against the Government and militants from the Taleban-style al-Shabaab movement were among those bearing down on the coastal town of Haradhere yesterday, drawn by the lure of political capital and pirate gold.

Tribesmen in outlying villages prepared to defend the town from possible attack, raising the prospect of a clash with the hardline al-Shabaab, who claimed that they had arrived to stamp out the pirate menace.

Residents, however, said they feared that the influx was a prelude to a bloody fight over the ransom money. The pirates have reportedly demanded $25 million (£17 million) in cash from the Saudi owners of the ship in return for the release of 25 hostages on board, including the Britons Peter French and James Grady.

“There are many militiamen who have arrived in the town and they want to get a share from the pirates if the ransom is paid,” Ahmed Abdullahi, a local elder, said. “They believe this ship is huge and the owner will pay a lot of money.”

The rush to Haradhere underlines one of the biggest concerns in the current crisis: no one can be sure where the pirates' takings are going or what they are funding, only that they are certain to fuel the violence - and the piracy it has spawned - for even longer.

Fears that the booty could end up in the hands of Islamist extremists, despite their long opposition to piracy, have stoked fears that they could finance the export of their militant ideology from Somalia.

The Kenyan Government said yesterday that the Somali pirate trade had brought in $150 million in ransom money over the past year. “That is why they are becoming more and more audacious,” Moses Wetangula, the Foreign Minister, said. Britain and Saudi Arabia's foreign ministers called on shipping companies not to pay ransoms for fear of encouraging piracy but the companies and shipping unions hit back, saying that they had no choice given the international failure to prevent piracy in the first place.

“Mr [David] Miliband is correct to say that ransom payments encourage further hostage-taking but the answer is not to refuse to pay them - it is to prevent the attacks from occurring in the first place,” said Mark Dickinson, the assistant general secretary of Nautilus, the seamen's union.

Foreign navies are rushing warships to the Gulf of Aden - 14 currently patrol the coastline and the European Union plans to send up to ten more next month under a centralised British command.

Shipping analysts say that such action is merely a “sticking plaster” until a solution to end the conflict in Somalia is found.

Somalia, in the words of the International Crisis Group, is going through “the darkest period in its recent history, which is a lot to say of a country that has not known a functioning government in almost a generation”.

The most stability it had in recent years was under the Islamic Courts government ousted in 2006 by Ethiopian troops backed by the United States, which was nervous that the region could become a haven for Islamic terrorists.

That move is now almost universally deemed to have been a failure, plunging Somalia back into factional fighting under a collapsing Western-backed transitional Government headed by a President, Abdullahi Yusuf, whose own tribe is deeply involved in the pirate trade.

The collapse of the economy in his ancestral homeland, Puntland, is blamed in part for the surge in piracy.

Under the Islamic Courts government, piracy was curtailed, although a question mark hangs over the motivation for the crackdown, given the handy side-effect of denying profits to its enemies.

Of the different factions that made up the Islamist Government, two are regarded as internationally unacceptable because of their al-Qaeda links. Many believe that the best chance of stability would be to isolate them from their allies, who could then be included in government.

One of them, al-Shabaab, said that it had sent its fighters to Haradhere not to share in the spoils, but to halt the pirate trade. “The Islamists arrived searching for the pirates and the whereabouts of the Saudi ship,” a Haradhere elder said. “The Islamists say they will attack the pirates for hijacking a Muslim ship.”

While there is no evidence of al-Qaeda involvement, there are signs that it may be watching. Writing on a militant website, one Islamist supporter noted that the influx of Western navies to the Gulf of Aden presented a golden opportunity for the kind of attack launched on the USS Cole in Yemen in 2000. “The enemies of al-Qaeda ... will swallow the bait and come to the area in which al-Qaeda has woven its nets,” he wrote. “At that time, al-Qaeda will settle scores with America and its allies.”

Times Recommends

• 'Radio Rancid' is scourge of Obama
• French gulp as global warming alters wines
• Colton, the barefoot boy bandit, outfoxes sheriffs