sources in Somalia say hundreds of al-Shabab militants left the town of Eldhere in the Galgadud region late Saturday and began heading east toward Harardhere in south Mudug. Harardhere is home to hundreds of pirates, who are holding at least six vessels and more than 90 people hostage.
The pirates began retreating with the hijacked vessels and crew to Hobyo, another pirate stronghold about 108 kilometers to the north.
Al-Shabab, which has proclaimed allegiance to al-Qaida and is considered a terrorist group by the United States and several other Western nations, controls most of southern Somalia and has been fighting for several years to topple the U.N.-backed, African Union-protected government in the Somali capital Mogadishu.
In recent days, al-Shabab said it had taken over control of three towns in the Galgadud region from the rival, pro-government Ahlu-Sunna Wal-Jama'a militia. The three towns, including Eldhere, are on the main road that leads to the capital.
But observers say in targeting Harardhere, al-Shabab's motive may be revenge-driven.
The Program Coordinator for the Nairobi-based East Africa Seafarers' Association, Andrew Mwangura, says he believes al-Shabab could be threatening to take Harardhere from pirates as punishment for the recent hijacking of a ship from Yemen, which was allegedly carrying arms for the extremist group.
He says al-Shabab is also fuming over last month's hijacking of nine Indian-owned vessels off the coast of Somalia. The pirates seized the small ships, called dhows, after they left the southern port of Kismayo with cargo destined for the United Arab Emirates.
The extremist group controls several key sea ports in southern Somalia, including Kismayo. The port is believed to generate millions of dollars in revenue for al-Shabab.
"These nine Indian dhows were laden with charcoal. And you know, charcoal export is part of money-making for al-Shabab. It is part of their revenue. You cannot operate out of the port of Kismayo without paying al-Shabab."
Most of the dhows have since been freed, but the hijackings prompted the Indian government to ban Indian-flagged vessels from sailing anywhere near Somalia. Mwangura says it is possible al-Shabab is angry about the loss of potential revenue caused by the ban.
This is not the first time al-Shabab has moved against pirates in Harardhere. In May, 2008, al-Shabab briefly seized Harardhere and declared piracy illegal before retreating. Five months later, several carloads of al-Shabab fighters entered Harardhere to demand the release of a hijacked Saudi Arabian supertanker, Sirius Star.
Western counter-terrorism officials have long worried that some of the money from piracy is making its way into the hands of extremists to fund violence in Somalia. But complex clan structures, shifting alliances, and an ungoverned black market have thwarted efforts to establish a solid connection.