Somali pirates have hijacked a Yemeni cargo ship, reported to be the 39th successful hijacking by pirates off the Horn of Africa this year.
Head of the East African Seafarers' Association Andrew Mwangura said the MV Amani was taken in the Gulf of Aden.
News of its capture comes 10 days after the giant Saudi super-tanker, the Sirius Star, was hijacked with $100m of oil and 25 crew members.
A pirate aboard the Sirus Star told the BBC the crew would not be harmed.
The man, calling himself Daybad, also said pirates had not yet negotiated with the Sirius Star's owners, but had only spoken to intermediaries who "cannot be trusted".
The ship's Polish captain told the BBC that his crew were in good shape.
Earlier, a group of tanker owners called on the UN to co-ordinate naval patrols off the coast of Somalia.
Peter Swift, head of the International Association of Independent Tanker Owners (Intertanko) suggested that warships could begin monitoring vessels leaving Somali waters, rather than attempting to patrol the entire Gulf of Aden and a significant part of the Indian Ocean.
He said the other option was a blockade around Somalia.
However, Nato Secretary General Jaap de Hoop Scheffer said on Monday that the alliance was not considering any naval blockade.
He said that such action has not been endorsed by the UN Security Council. Nato has four warships on duty in the area.
EU foreign policy chief Javier Solana told a meeting of the European Union in Brussels on Monday that EU ships patrolling the area would use force to deter pirates if necessary.
"I would like to say on behalf of the European Union that the mission will have rules of engagement that will be robust, with all means to protect, to deter and it will include the use of force," he said.