NAIROBI (AFP) – Somali pirates hijacked a Chinese bulk carrier Monday northeast of the Seychelles in the Indian Ocean, as the marauding sea bandits hunted their prey ever further from base to wrong-foot naval patrols.

According to the European Union's anti-piracy naval mission (EU NAVFOR), the unnamed ship was seized 550 nautical miles (1,000 kilometres) northeast of the Seychelles and 700 nautical miles off the east coast of Somalia.

"On indication of an attack an EU NAVFOR Maritime Patrol Aircraft, operating from the Seychelles was launched to investigate the incident," the EU naval mission said in a statement from its headquarters in Britain.

The ship was not registered with the force's Horn of Africa Maritime Security Centre, the statement added.

EU naval spokesman John Harbour told AFP the ship had a crew of 25, all of them Chinese nationals.

Chinese state media said the ship's name was De Xin Hai and was carrying coal. China's Ministry of Transport said relevant government agencies were making efforts to rescue the ship, which was en route from South Africa to India, according to Xinhua news agency.

According to maritime sources in the Indian Ocean, it is the first time pirates have boarded a merchant vessel east of the 60th meridian, between the Seychelles and Maldives archipelagos.

The capture of the Chinese ship brings to six the total number of vessels currently in the hands of Somali pirates.

According to non-governmental observers Ecoterra International, at least 179 attacks have been carried out by Somali pirates since the start of 2009 alone, 52 of them successful hijackings.

Since last year a flotilla of foreign warships has been patrolling the Gulf of Aden, one of the busiest maritime trade routes on the globe, prompting pirates to operate far out in the Indian Ocean.

Experts had warned in recent days that subsiding winds near the Seychelles had attracted pirates, who generally launch attacks from so-called "mother ships" with tiny skiffs.

Pirates focus most of their attacks on transitional weather periods between monsoons when the seas are calm enough for them to operate. This year's summer season came later than last year. Related article: France to support Seychelles courts

The Seychelles, a tiny nation already hard-hit by the global financial crisis, has pleaded for international help in fighting piracy.

Joel Morgan, the island state's minister in charge of anti-piracy, said Sunday during a visit by French Defence Minister Herve Morin that maritime traffic in the area had dropped by a third due to piracy.

The Seychelles economy is highly reliant on revenue from high-end tourism, including cruises, as well as on a tuna-fishing industry whose trawlers have come under attack over the past year.

France has deployed troops on some of its fishing fleet there while Spanish trawlers had enlisted private security after the government deemed it illegal to grant state military protection.

According to Madrid's El Pais daily, eight Spanish ships are currently employing former British soldiers -- including Gurkhas -- supplied by British security firm Minimal Risk.

A Singaporean-flagged container vessel seized on Thursday near the Seychelles has now reached Somali waters, near the pirate hub of Hobyo, said Andrew Mwangura, head of East African Seafarers Assistance Programme.

He said a naval vessel was shadowing the MV Kota Wajar, with its cargo of 360 containers and crew of 21 from Singapore, India, Pakistan, China, Indonesia, Sri Lanka and Myanmar.

Ecoterra said in a statement that the newly-hijacked ship's captain transferred some of his fuel to the nearby MV Ariana, a Maltese-flagged ship owned by a Greek company and carrying a Ukrainian crew.

During long hijackings, fuel is crucial to powering generators that can run communication equipment, refrigerators where food and medical supplies are kept and bilge pumps.