Kuala Lumpur (AsiaNews/Agencies) – The International Maritime Bureau reported today that 35 men armed with machine guns and rocket launchers stormed a ship in the Strait of Malacca that was transporting gas from Kalimantan, in Borneo, to Bulawan, in Sumatra.

The attackers ordered the crew to sail towards Dumai district on a different part of Sumatra Island before disappearing with the Japanese captain and chief engineer and a Filipino engineer as their captives.

The ship owners are negotiating the hostages' release with the attackers, who have demanded a ransom and are suspected of being members of the Free Aceh Movement.

Japanese authorities have asked Malaysia, Indonesia and Singapore for help in releasing the hostages.

This was the second attack in the Malacca Strait following the December 26 tsunami, which some experts thought might have hurt the pirates.

Piracy has long plagued the 885km-long waterway between Sumatra Island and peninsular Malaysia. Every year, the shipping lanes in the Malacca Strait are used by about 50,000 ships. The International Maritime Bureau recorded 37 pirate attacks in 2004.