NEW DELHI (AP) -- The ship, operating off the coast of Oman in the lawless waters of the Gulf of Aden, was crewed by heavily armed men, some carrying rocket-propelled grenade launchers. Behind it were a pair of speedboats - the sort pirates often use when they launch attacks on merchant ships in these violent seas.
What followed, officials said Wednesday, was a rare victory in a sea war against Somalia-based piracy that has become increasingly more violent, and where the pirates are ever more bold.
A patrolling Indian navy frigate quickly identified the vessel as a "mother ship" - a mobile attack base used to take gangs of pirates and smaller speedboats into deep water - and ordered it to stop and be searched.
"They responded on the offensive and said that they would blow up the Indian naval ship," Commander Nirad Sinha, a navy press officer, told reporters in New Delhi. Then the pirates opened fire.
Navy officials wouldn't say how long the battle Tuesday lasted, but the frigate, the INS Tabar, is a 400-foot war machine, carrying cruise missiles, surface-to-air missiles and six-barreled 30 mm machine guns for close combat, according to the Web site GlobalSecurity.org.
By the time the battle was over, the mother ship had sunk - the Indian gunfire sparked fires and a series of onboard blasts, possibly due to exploding ammunition - and the speedboats were racing into the darkness.
One was later found abandoned. The other escaped. An unknown number of people died on the mother ship, a navy statement said.
It's not the first success. Last week, Indian navy commandos operating from a warship foiled a pirate attempt to hijack a ship in the Gulf of Aden. The navy said an armed helicopter with marine commandos prevented the pirates from boarding and hijacking the Indian merchant vessel.
Across the Gulf of Aden, though, news was far more grim for shippers.
Separate bands of pirates seized a Thai ship with 16 crew members and an Iranian cargo vessel with a crew of 25.
"It's getting out of control," Choong said.
A multicoalition naval force, which includes the Indian presence, has increased patrols in the region, but the seizures Tuesday raised to eight the number of ships hijacked this week alone, Choong said. Since the beginning of the year, 39 ships have been hijacked in the Gulf of Aden, out of 95 attacked.
"There is no firm deterrent, that's why the pirate attacks are continuing," Choong said. "The criminal activities are flourishing because the risks are low and the rewards are extremely high."
The pirates used to mainly roam the waters off the coast of Somalia, where there has not been a stable, functioning government in nearly 20 years. But now they are targeting ships far further out at sea.
Choong said 17 vessels remain in the hands of pirates along with more than 300 crew members, including a Ukrainian ship loaded with weapons and a Saudi supertanker carrying $100 million in crude.
The supertanker, the MV Sirius Star, was anchored Tuesday close to Harardhere, the main pirates' den on the Somali coast, with a load of 2 million barrels of oil and 25 crew members.
"We do not like to negotiate with pirates, terrorists or hijackers," but the owners of the tanker are "the final arbiter" on the issue, he said.
Pirates have generally released ships after ransoms were paid.
But U.S. Navy Commander Jane Campbell of the 5th Fleet said naval patrols simply cannot prevent attacks given the vastness of the sea and the 21,000 vessels passing through the Gulf of Aden every year.
White House press secretary Dana Perino said Wednesday that President George W. Bush has been briefed on the issue of piracy and that the United States was working with other members of the U.N. Security Council to see if there are actions that can be taken to fight and prevent piracy more effectively.
"The safety and well-being of the crew is of paramount importance in preventing or dealing with issues of piracy," Perino said. "One of the things that's clear is that piracy is something that is affecting ... many more waters than any of us would have known about."
The Gulf of Aden 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.
The Thai boat, which was flying a flag from the tiny Pacific nation of Kiribati but operated out of Thailand, made a distress call as it was being chased by pirates in two speedboats but the phone connection was cut.
"We have not heard from them since, so we don't know what the demands are," Wicharn said. "We have informed the families of the crew but right now, we don't have much more information to give them either."
Of the 16 crew members, Wicharn said 15 are Thai and one is Cambodian.
"Based on previous cases, we believe they were held for ransom. We are optimistic that we will be able to negotiate for their release once we can contact the ship," he told the AP.
On Tuesday, a major Norwegian shipping group, Odfjell SE, ordered its more than 90 tankers to sail around Africa rather than use the Suez Canal after the seizure of the Saudi tanker.
"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.
Barbara Surk in Dubai, United Arab Emirates; Vijay Joshi in Kuala Lumpur, Malaysia; Ambika Ahuja in Bangkok, Thailand, and Mohamed Sheikh Nor and Mohamed Olad Hassan in Mogadishu, Somalia, contributed to this report.