Heavily-armed Somali pirates seized a Danish-managed general cargo ship with 13 crew off the coast of Somalia, a maritime watchdog said today.

Noel Choong, head of the International Maritime Bureau's (IMB) piracy reporting centre in Kuala Lumpur, told AFP Somali pirates hijacked the ship on Friday at 1240 GMT in the pirate-infested Gulf of Aden, off the coast of Somalia.

The vessel was heading from the Middle East to Asia and flying the national flag of the Bahamas.

"The ship has been captured by the pirates," Choong said.

"These attacks are going up, despite the increase in international patrols and we are concerned over the ongoing attacks and hijackings," he added.

Choong said that the latest incident brought to 81 the number of attacks in the area this year. The total includes 32 hijackings, of which 11 ships and more than 200 crew are still being held by Somali pirates.

Well-organised pirates

The latest hijacking follows the capture of a Turkish-operated bulk carrier with 20 sailors on board last week as it travelled from North America to Asia.

Pirates are well-organised in the area where Somalia's northeastern tip juts into the Indian Ocean, preying on a key maritime route leading to the Suez Canal through which an estimated 30 percent of the world's oil transits.

The pirates operate high-powered speedboats and are heavily armed, sometimes holding ships for weeks until they are released for large ransoms paid by governments or owners.

NATO warships, along with ships and aircraft from several other nations have been deployed in the region to protect commercial shipping.

- AFP