Athens/Nairobi - Saudi Arabia's foreign minister on Tuesday called the hijacking of a Saudi oil tanker by Somali pirates an "outrageous act."

In the first Saudi Arabian public statement about the hijacking, Prince Saud al-Faisal said there is a need to fight piracy.

"Piracy, like terrorism is a disease which is against everybody, and everybody must address it together," he said in Athens following talks with Greek Foreign Minister Dora Bakoyianni.

The tanker Sirius Star, which was sailing under a Liberian flag, was seized by Somali pirates on Saturday 450 nautical miles south-east of the Kenyan coastal city of Mombasa.

Somali pirates often take their ships to anchorage near the pirate stronghold of Eyl, in the semi-autonomous northern region of Puntland, where they keep international warships at bay by holding crew members hostage.

Ship-owner Vela International, a subsidiary of Saudi Arabian oil company Saudi Aramco, said in a statement on its website that the ship was carrying a full load of crude oil when it was seized.

The Sirius Star, which is 330 metres long, can carry up to 2 million barrels of oil, meaning its cargo is worth some 100 million dollars.

However, the pirates, who operate out of small launches from a mothership, do not have the capability to unload the crude and are expected to hold the ship to ransom.

The ship's 25 crew members, who are from Britain, Croatia, the Philippines, Poland and Saudi Arabia, are all safe, Vela International said in a statement.

No contact has yet been made with the pirates, but Vela said it had set up response teams to negotiate the safe release of the crew members and the tanker.

The US Navy is monitoring the path of a hijacked Saudi oil tanker as it makes its way to anchorage off the coast of Somalia but does not plan any action to recover the ship, a US Navy official said Tuesday.

The ship is the largest to have been taken by pirates in a series of hijackings in the area over the past months and represents their most daring raid yet.

The attack took place well outside the normal danger areas in the Gulf of Aden and off the coast of Somalia.

The Gulf of Aden is a busy shipping channel which forms part of the route linking the Indian Ocean with the Mediterranean Sea through the Suez canal.

The International Maritime Bureau says that 63 attempted attacks of piracy took place off the coast of Somalia in the first nine months of this year.

Since these figures were released in October, there have been several dozen new attacks.

At least 12 ships with about 250 crew members continue to be held by pirates. Those include a Ukrainian freighter, the MV Faina, that was captured while carrying 33 military tanks to Mombasa.

Over 30 ships have been successfully seized so far this year.

The surge in piracy has prompted increased patrols by the North Atlantic Treaty Organization, Russia, the US-led coalition forces 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 in early December. Greece, which relies heavily on its shipping industry, has contributed a frigate and helicopter to help with patrols.

However, the pirates appear undaunted by the increased naval presence and continue to attack ships in search of multimillion-dollar ransoms.

A report released by London-based independent think tank Chatham House in October said that pirates had scooped up to 30 million dollars from ransoms in 2008.

The surge in piracy off Somalia has coincided with a rise in violence in Somalia itself, where authorities in the central and southern region are battling a bloody insurgency.

The weak central government has been unable to suppress either the insurgency or the growing piracy.

Somalia has been engulfed in chaos and civil war since the fall of dictator Mohamed Siad Barre in 1991. (dpa)