MOGADISHU, Sept. 5 (Xinhua) -- Ahmedou Ould-Abdallah, UN envoy for Somalia, on Friday expressed "extreme alarm" at the increase in piracy against ships both in Somali waters and in international waters near Somalia.

    "This piracy is increasingly a threat to international navigation and free trade in an already fragile environment," said Ould-Abdallah, UN special representative for Somalia, in a statement received here.

    The millions of dollars in ransom paid to the pirates and their associates inland and overseas has become a multi-million dollar business which threatens stability in Somalia as a whole, he added.

    More than 30 ships, 11 of them in the past two months alone, have been attacked this year, making that stretch of the coastline one of the most dangerous in the world.

    In the latest cases, heavily armed Somali pirates abducted an Egyptian-flagged ship and a French tourist yacht off the coast of northeastern Somalia this week. The pirates demanded five million U.S. dollars of ransom for the release of the French yacht and two French nationals aboard.

    "We have to work quickly before the level of criminal activity increases and affects ports in neighboring countries. We must work together to put an end to this terrible scourge," said Ould-Abdallah.

    He welcomed the passing last June of a UN resolution authorizing members to use force to stop piracy, saying that "the international community has shown its determination to stop these criminals".

    However, he said, "these criminals are challenging this Security Council resolution and the time has come for a collaborative effort to put the resolution into effect".

    The Horn of Africa nation's coastline is considered one of the world's most dangerous stretches of water because of piracy.