Somali pirates have built up their defences around a captured Saudi Arabian super-tanker after reportedly demanding a $US25 million ransom.
The Sirius Star, the biggest ship ever hijacked, and its $US100 million cargo of oil was seized on 15 November and taken to Harardhere, 300km north of Somalia's capital Mogadishu.
As foreign navies sent warships to Somalia's dangerous waters and shipping companies sought alternative routes, extra clan militia and other fighters were brought in to Harardhere, residents said on Friday.
Local militia and hardline Shebab fighters have also arrived in what some residents said was a move to position themselves for a share of any ransom paid.
"There are two armed vehicles belonging to al Shebab. They have reached the town of Harardhere but there are no intentions of attacking the ship from here," a Harardhere Islamist official said by phone.
The militiamen want a share from the pirates if the ransom is paid, said Ahmed Abdullahi, a local elder. "They believe this ship is huge and the owner will pay a lot of money."
The pirates on Thursday gave the owners 10 days to pay the ransom.
However the company conducting negotiations on behalf of the tanker's owners has denied the figure of $US25 million has been demanded in ransom, reports the BBC.
The BBC also reports shipping industry experts expect the ransom for the tanker to be much higher.
Speaking from the tanker, a pirate who identified himself as Mohamed Said threatened "disastrous" consequences should Vela International, shipping arm of the Saudi oil giant Saudi Aramco, fail to comply.
He did not specify the threatened action but the 330-metre-long tanker is carrying two million barrels of crude oil.