Nairobi/Berlin - Somali pirates have seized a Liberian- flagged ship in the Gulf of Aden, although several crew members managed to escape overboard and were picked up by a German Navy helicopter, US Navy and German officials said Friday.

"The Liberian-flagged tanker Biscaglia was successfully attacked today in the Gulf of Aden," Commander Jane Campbell of the US Navy's Fifth Fleet told Deutsche Presse-Agentur dpa.

"Two helicopters from a coalition ship found several people in the water and transferred those individuals to a French ship that is on national tasking," she added.

A spokesman for the German Ministry of Defence said that a helicopter from the frigate Mecklenburg Vorpommern lifted three crew from the sea after responding to an emergency call.

The pirates had already successfully boarded the Biscaglia by the time the helicopter arrived, the Ministry of Defence said.

There are reportedly three Indonesians, 25 Indians and two British security officers onboard the ship.

The incident was the latest in a long line of attacks on ships in the Gulf of Aden.

Piracy off the coast of Somalia has surged in recent months as a bloody insurgency in the country worsens and the ineffectual central government continues to squabble rather than govern.

According to the International Maritime Bureau (IMB), there have been almost 100 attempts at piracy in the region this year, with around 40 of them successful.

Around 16 ships are in the hands of pirates along with over 300 crew members, including Saudi supertanker the Sirius Star, which was carrying 100 million dollars worth of crude oil when it was taken.

The Sirius Star was moved from its anchorage point last week after Islamist insurgents threatened to attack the pirates for seizing a ship from a Muslim country.

Negotiations are underway between the ship's owner Saudi Aramco and the pirates.

Normally hijacked ships are ransomed off for several million dollars, although the latest asking price for the Sirius Star is fifteen million dollars.

However, security forces from the semi-autonomous Puntland region, where most of the pirates are based, have said they are planning to storm the Yemeni ship Erina after its owner refused to pay a ransom.

The Philippines' Department for Foreign Affairs said Friday that the Greek-owned MV Centauri with 26 Filipino crew had been released on Thursday. It was not clear if a ransom was paid.

The surge in piracy has prompted increased patrols by the North Atlantic Treaty Organization, Russia, US-led forces, India and France along the Somali coast.

The European Union has also authorized a force of between five and seven frigates, which is expected to arrive in the Gulf of Aden early December.

So far, however, the increased naval presence has failed to curb the pirate attacks.

The Indian Navy frigate INS Tabar sank a suspected pirate mothership on November 18, but vessel is now believed to have been a Thai-owned fishing boat. (dpa)