The Saudi foreign minister says the owners of a hijacked oil tanker are negotiating with the pirates that are holding it.

Prince Saud Al-Faisal spoke Wednesday after talks in Rome with his Italian counterpart.

Asked if he could confirm reports that a ransom had been demanded, he said the owners of the tanker "are negotiating on the issue" but did not elaborate.

He says the Saudi government does not like to negotiate with "pirates, terrorists or hijackers" but the owners of the tanker are "the final arbiter" on the issue.

The MV Sirius Star was seized off the Kenyan coast Saturday with 25 crew members and has been taken to a pirate stronghold off the Somali coast. The ship's oil cargo alone is estimated to be worth $100 million.

Click here for photos.

A man believed to be one of the masterminds behind the attack said on al-Jazeera television Wednesday that the pirates had demanded a ransom from the ship's owners.

"Negotiators are located on board the ship and on land. Once they have agreed on the ransom, it will be taken in cash to the oil tanker," said the man identified as Farah Abd Jameh, who did not indicate the amount to be paid.

"We assure the safety of the ship that carries the ransom. We will mechanically count the money and we have machines that can detect fake money," the man said on an audio tape produced by the Dubai-based television network.

The message came as two more ships were seized by Somali pirates in the past 24 hours: a Greek bulk carrier and a Thai fishing boat, despite a large international naval presence in the waters off their lawless country. An Iranian cargo ship was also hijacked earlier in the week.

Meanwhile, a major Norwegian shipping group ordered its tankers to sail around Africa rather than use the Suez Canal because of the hijack risk.

The U.S. and other naval forces decided against intervening in the seizure of the supertanker, which was carrying $100 million in crude. The pirates captured an Iranian cargo ship Tuesday — the eighth ship seized in 12 days.

Odfjell SE said it made the decision to divert its ships after pirates seized the Saudi Arabian supertanker MV Sirius Star Saturday hundreds of miles off the coast of Kenya, the most brazen attack yet by Somalian pirates.

"We will no longer expose our crew to the risk of being hijacked and held for ransom by pirates in the Gulf of Aden," said Terje Storeng, Odfjell's president and chief executive. "Unless we are explicitly committed by existing contracts to sail through this area, as from today we will reroute our ships around Cape of Good Hope."

Noel Choong of the International Maritime Bureau said the Thai boat was seized in the Gulf of Aden on Tuesday as it traveled toward the Mideast.

The vessel was captured the same day that pirates hijacked an Iranian bulk cargo carrier with 25 crew members. Saturday's attack on the Saudi supertanker was the most brazen attack in the region yet.

The Gulf of Aden, off Somalia, connects to the Red Sea, which in turn is linked to the Mediterranean by the Suez Canal. The route is thousands of miles and many days shorter than going around the Cape of Good Hope off the southern tip of Africa.

"This will incur significant extra cost, but we expect our customers' support and contribution," said Storeng.

"Odfjell is frustrated by the fact that governments and authorities in general seem to take a limited interest in this very serious problem," he added, describing the seizures as "ruthless, high-level organized crime."

Pirates have seized dozens of ships off Somalia's coast in the last year, generally releasing them after ransoms were paid. NATO has three warships in the Gulf of Aden and the U.S. Navy's 5th Fleet has ships in the region. But the MV Sirius Star was seized far from where they patrol.

While Somali pirates have seized 36 ships over the past year, among them a Ukrainian ship loaded with arms that is still being held, never had they seized a vessel as large as the Sirius Star and so far out to sea. The tanker was more than 450 nautical miles southeast of Mombasa, Kenya, an area far south of the zone where warships have increased their patrols.

Saudi Foreign Minister Prince Saud al-Faisal called the hijacking "an outrageous act" and said "piracy, like terrorism, is a disease which is against everybody, and everybody must address it together."

The kingdom, which is the world's leading oil producer, said it will join the international fight against piracy, and Somali officials vowed to try to rescue the supertanker, by force if necessary.

The Sirius Star was anchored Tuesday close Harardhere, the main pirates' den on the Somali coast, with a full load of 2 million barrels of oil and 25 crew members.

"As usual, I woke up at 3 a.m. and headed for the sea to fish, but I saw a very, very large ship anchored less than three miles off the shore," said Abdinur Haji, a fisherman in Harardhere.

"I have been fishing here for three decades, but I have never seen a ship as big as this one," he told The Associated Press in a telephone interview. "There are dozens of spectators on shore trying to catch a glimpse of the large ship."

He said two small boats floated out to the ship and 18 men — presumably other pirates — climbed aboard with a rope ladder. Spectators watched as a small boat carried food and qat, a narcotic leaf popular in Somalia, to the supertanker.

Salah B. Ka'aki, president and CEO of the tanker's owner Vela International Marine Ltd, said the oil tanker's 25 crew members "are believed to be safe." The statement said they were awaiting further contact from pirates controlling the vessel.

With naval forces unwilling to intervene, shipowners in past piracy cases have ended up paying ransoms for their ships, cargos and crew.

The Iranian ship was a bulk cargo carrier flying a Hong Kong flag and operated by the Islamic Republic of Iran Shipping Lines. U.S. Navy Commander Jane Campbell of the Bahrain-based 5th Fleet said the status of the crew and cargo was not known.

The International Maritime Bureau on Sunday reported five hijackings since Nov. 7, before the Saudi, Iranian and Thai ships were announced.

Saud, speaking during a visit to Athens on Tuesday, said Saudi Arabia would join an international initiative against piracy in the Red Sea area, where more than 80 pirate attacks have taken place this year.

He did not elaborate on what steps the kingdom would take to better protect its vital oil tankers. Saudi Arabia's French-equipped navy has 18,000-20,000 personnel, but has never taken part in any high-seas fighting.

Abdullkadir Musa, the deputy sea port minister in northern Somalia's breakaway Puntland region, said if the ship tries to anchor anywhere near Eyl — where the U.S. earlier said it was heading — then his forces will try to rescue it.

Forces from Puntland region in northern Somalia have sometimes confronted pirates, though Somalia's weak central government, which is fighting Islamic insurgents, has been unable to mount a response to increasing piracy.

Puntland forces, their guns blazing, freed a Panama-flagged cargo ship from pirates on Oct. 14.

In Vienna, Ehsan Ul-Haq, chief analyst at JBC Energy, said the seizure was not affecting oil prices because traders were focused instead on "the overall economy."

The U.S. Navy is still surrounding a Ukrainian ship loaded with tanks and other weaponry that was seized by pirates Sept. 25 off the Somali coast.

The Times of London and Associated Press contributed to this report.