A UN-chartered aid ship hijacked by Somali pirates three months ago has left the port where it was expected to unload and sailed to uncertain destination with ten hostages on board, apparently under new demands from the pirates, UN officials said here Friday.

On Monday, the pirates brought the vessel into El Maan port, north of Mogadishu, after protracted negotiations to end the three- month standoff in the lawless Indian Ocean waters off Somalia.

But on Thursday, the UN-chattered ship left again with the food and hostages on board after the pirates apparently issued new ransom demands as the authorities prepared to unload the cargo of 850 tons of rice.

"The ship has left the port of El Maan apparently to Mogadishu. This follows the expiry of the 1 p.m. on Thursday deadline set by port authorities for the hijackers to offload the cargo and release the crew," UN World Food Program (WFP) spokesperson Robin Lodge said by telephone.

"They (the pirates) also issued new ransom demands, including re-imbursement for fuel and engine oil," Lodge said, without elaborating.

Sources said the pirates, who have alternately demanded a ransom payment and the 850 tons of rice for the release of the ship and crew, asked for 100,000 US dollars to offload the food and transport it by land back to Haradhere.

They had initially demanded 500,000 dollars in ransom, but the WFP has repeatedly refused to pay any ransom for the release of the ship, its crew and cargo.

The MV Semlow was carrying WFP aid for Somali victims of the Indian Ocean tsunami, when it was seized off the Somali coast between Haradhere and Hobyo, some 400 km northeast of the capital Mogadishu on its way to the Gulf of Aden port of Bossaso, in the self-declared autonomous region of Puntland.

The militiamen have been holding the MV Semlow -- with 10 crew members from Kenya, Tanzania and Sri Lanka since June 28.

"It got so close and I really thought we were coming to an end of this. The port authorities said they would not allow the ship to stay," said Lodge.

The WFP had announced a breakthrough in the negotiations on August 6 only for the pirates to renege later forcing the UN to renew appeal for their release.

Some 28,000 people who lost their homes and livelihoods when the tsunami struck on December 26 are being fed by the United Nations.

Somalia is awash with some 60,000 militia men and has been without a functioning national government since 1991, which hampered relief efforts to tsunami victims.

The WFP hijacking was the sixth reported piracy incident in Somali waters since March, including one in early June in which a US naval destroyer intervened to save a vessel under attack.

The International Maritime Board has warned of an alarming increase in piracy in Somali waters and has urged ships to avoid the area.

Source: Xinhua