Pirates holding ships off Harardhere in central Somalia are moving them after disputes over ransom sharing with the Al-Qaeda-linked rebels controlling the town, local sources said Friday.

Pirate sources in the nearby pirate lair of Hobyo, off the shores of which most of the 40-plus vessels currently hijacked are now anchored, said Shebab fighters in Harardhere were asking for 20 percent of the ransom payments.

Local businessmen who finance part of the pirates' operating costs in exchange for a share of the ransoms refused, resulting in the arrest of four of them by the Shebab.

"The Islamists have arrested four of our investors. They asked for a 20-percent share of ransoms expected to be paid for ships held off Harardhere, but the investors rejected the demand," Abdi Yare, a Hobyo pirate chief, said.

"There were around nine ships -- three of them big ones -- held off Harardhere but the ships started shifting from the area because of the disputes," he told AFP.

Hobyo, north of Harardhere, is controlled by clans hostile to the Shebab.

Abdikarim Moalim, a fisherman near Hobyo, said one of the ships that left Harardhere because of the argument anchored off Hobyo late Thursday.

He said the hijacked vessels held off Harardhere, the small town where modern Somali piracy originated in 2003-2004, were being moved north to Hobyo and Labad.

Another pirate who asked not to be identified also confirmed the arrests.

The Shebab, who control most of south and central Somalia, were initially opposed to piracy, arguing it is outlawed under Islam.

Piracy operations have however been conducted from Shebab-controlled areas recently, suggesting some form of arrangement between the two sides.

The Shebab have failed to break the back of the transitional federal government in Mogadishu despite a two-year-old offensive and are constantly looking for new sources of funding.

So far, there has been no evidence however of Shebab fighters actively conducting piracy operations or benefiting from piracy in any other way than by charging a "docking fee" to pirates active in areas they control.