NAIROBI, Feb. 5 (Xinhua) -- Somali pirates holding a Ukrainian ship containing tanks and other weapons have received 3.5 million U.S. dollar ransom they have been demanding, a regional maritime body said on Thursday.

　　A statement from the Ecoterra International said ransom had been paid and the pirates were counting and dividing up the money aboard the MV Faina in the Gulf of Aden.

　　However, maritime officials said several difficulties remain to be worked out before the release of the Ukrainian vessel which was captured in September with its 20-man crew and a cargo of Soviet-era T-72 tanks and other weapons.

　　"The talks had been concluded and the ransom has been delivered today, but the vessel is not free yet and the Faina saga always has been full of surprises," Ecoterra said in its newsletter.

　　In November, negotiators said the owners had agreed to pay the pirates a ransom. The pirates originally asked for 35 million U.S. dollars before lowering their demand to 3.5 million U.S. dollars.

　　About 20 Ukrainian, Russian and Latvian crewmembers have been held on the ship since the capture of the ship. Parents of the Ukrainian crew have complained that their sons are being held in "horrible" conditions.

　　Pirates captured the ship in September as it headed to Kenya with its cargo of Russian-made T-72 tanks, ammunition and other military hardware.

　　The MV Faina is currently moored off Somalia's coast close to the town of Hobyo. There have been conflicting reports of where the Faina and its cargo were destined.

　　Kenya has said it was the intended recipient of the cargo. But maritime officials and diplomats in the region said it was destined for the government of southern Sudan.

　　The waters off Somali coast are considered to be some of the world's most dangerous. Pirates have hijacked several ships last year and attacked many more.

　　Most attacks have been in the Gulf of Aden between Yemen and north Somalia, a major route leading to the Suez Canal linking Europe and Asia.