Indonesia's navy has deployed three ships to seek the release of five hostages two Japanese, one Filipino and two Indonesians kidnapped by armed pirates in the Malacca Strait, a spokesman said Tuesday.

The crewmen were snatched in two separate incidents in waters around the Malacca Strait, a busy shipping lane plagued by pirates who prey on vessels that carry a third of world trade and half of its oil supplies.

A Japanese-registered tugboat was hijacked late on Monday by a group of armed pirates in the Strait off the Malaysian coast around Pangkor, Indonesian Navy Spokesman First Admiral Abdul Malik Yusuf said.

"We immediately sent three navy boats to the area to look for the hijackers and the tugboat," Yusuf said.

He said that the assailants used three fishing boats in their attack shortly before dusk. The navy believed the hijackers and their hostages were now in an area southwest of Malaysia's Penang Island and west of Pangkor Island.

The tugboat and the three hostages two Japanese and one Filipino were taken by their abductors to an unknown location. Eleven other crewmen were released and were reported to be safe.

On Sunday, armed pirates also boarded an Indonesian-registered ship, the Tri Samudra, that was transporting 1,300 tonnes of methanol from Samarinda in East Kalimantan Province to the North Sumatran port of Belawan.

Lieutenant Colonel Edi of the Indonesian eastern fleet information center said the hijackers took cash and fled with two hostages the captain and the chief engineer.

The vessel, and a crew of 12, were taken by the navy to Belawan port, Edi said.

"The head of the Dumai navy base is currently on board a warship to try to locate the pirates and their hostages," Edi said.

Dumai, in Indonesia's Riau Province, lies on Sumatra Island's Malacca coast.

He said that the abductors of the two Indonesians have already demanded a ransom of 2 billion rupiah (US$214,000) from the boat owner, Humpuss Intermoda Transport.

The company could not be immediately reached for comment.

The narrow 960-kilometre Malacca Strait, bordered by Malaysia, Singapore and Indonesia, is used by about 50,000 ships a year.

Japan said yesterday it was doing its utmost to secure the release of two Japanese and one Filipino who were kidnapped by armed pirates from a Japanese-registered tugboat in the Malacca Strait.

Japanese Prime Minister Junichiro Koizumi ordered government agencies to work to rescue the three while Chief Cabinet Secretary Hiroyuki Hosoda said Tokyo had yet to make contact with the hostage takers.

"We do not know their objective of kidnapping the three. They have not contacted us," Hosoda, Japan's government spokesman, told a news conference.

Japan's coast guards are considering dispatching patrol vessels and airplanes to the area if Malaysia makes such a request, a coast guard official said.

Japan's Foreign Ministry set up a task force to handle the crisis and asked Malaysia, Indonesia and Singapore for help, Foreign Minister Nobutaka Machimura told reporters.

(China Daily March 16, 2005)