By Jeremy Clarke NAIROBI, April 7 (Reuters) - Two ships hijacked by pirates off the anarchic Somali coast have been released, including one that had been carrying United Nations food aid, a maritime organisation said on Saturday. The ships -- a merchant vessel seized close to Mogadishu last week and a U.N.-chartered freighter captured in late February -- are en route to the Kenyan coast, said Andrew Mwangura, director of the East African Seafarers Assistance Programme. "Both the MV Nimatullah and the Rozen have been released. They are on the move from Somali waters and we are expecting them to dock in Mombasa in the next four or five days," he said. The hijackers had also released the crew members, 12 on the Rozen and 14 on the Nimatullah, who are in good health, he said. It was not immediately clear if any ransom had been paid. The WFP (World Food Programme) welcomed the release of the Rozen 40 days after its capture near the tip of the Horn of Africa, and thanked elders from the semi-autonomous Puntland region for brokering its release. "The threat of piracy is still very much alive in Somali waters and WFP urges the transitional federal government of Somalia and the Puntland authorities to curb this menace," WFP Somalia Country Director Peter Goossens said in a statement. The hijacking of the U.N.-chartered Rozen was the first attack reported since the Somali interim government, with Ethiopian military help, late last year drove out Islamists who controlled southern Somalia. The Islamists had vowed to crack down on piracy as an affront to Islamic law, and did so -- but a U.N. report last year said they only acted after pirates stole a cargo of their weapons. The Rozen is the third U.N.-chartered ship hijacked in Somali waters in the last two years, and the fourth ship belonging to the Mombasa-based Motaku Shipping Agency seized during that period. The Rozen had just dropped off its cargo of food aid when it was caught. The Nimatullah, a Dubai-registered dhow, was chartered by a Somali businessman and was carrying 800 tonnes of consumer goods. Somalia's coastline -- Africa's longest -- is one of the most dangerous in the world because of pirates who prowl its unpatrolled waters, in the absence of a stable government since the overthrow of dictator Mohamed Siad Barre in 1991.