Saturday, 19 March, 2005, 11:46 GMT
The spokesman said the hostage-takers had not been identified, and he did not know whether a ransom was paid.
Search-and-rescue teams are still looking for the captain and two crewmen of a Japanese tugboat, kidnapped in the Malacca Strait on Monday.
Around a quarter of the world's trade and half of its oil supplies pass through the Malacca Strait, which is considered a hotspot for piracy.
The two Indonesians were kidnapped on Saturday or Sunday last week when a gang of more than 30 pirates armed with machine guns and rocket launchers boarded the Indonesian-registered ship.
The kidnappers demanded a ransom of two billion rupiah ($211,449, £110,000) from the owners of the ship.
A Japanese tugboat was attacked on Monday
On Monday, at least 10 pirates opened fire on a Japanese-flagged tug, the Idaten, and boarded it.
Eleven crew members made it safely to the Malaysian port of Penang, but the Japanese captain and engineer, and a Filipino crewman were captured.
On Friday Malaysian marine police said they had detained four Thais and a Malaysian suspected of involvement in the assault.
The Indonesian navy spokesman said the whereabouts of the hostages are still not known, but added: 'We hope that with the arrest in Malaysia they will soon be found.' "
This area was affected by the Tsunami. I wonder where the pirates hid out during the Tsunami.
Arrrrrr, me maties.