A mystery ship pursued over the weekend by Japanese Coast Guard and naval vessels fired two small rockets at its pursuers before it sank in the East China Sea. Video footage of a rocket launch was screened at the government's Security Council meeting Monday.
The Japanese Coast Guard says the 100-ton ship, believed to have been from North Korea, carried several weapons, including portable rocket launchers. That raises concern that Japan's patrol boats face greater dangers than previously believed.
One Coast Guard official called the incident the most dangerous mission ever conducted by the agency. Two of the Coast Guard patrol boats returned to port on Sunday riddled with bullet holes.
The captain of the Amami, one of the patrol boats that suffered damage, spoke to reporters. Captain Masao Kurusu says the mission was extremely dangerous but his crew carried out their policing duties.
At Monday's Security Council meeting, government officials say Prime Minister Junichiro Koizumi ordered an investigation to find out why 20 Japanese patrol boats backed up by 14 aircraft were unable to capture the vessel or its crew despite the hours-long chase.
All 15 people aboard the mystery ship are believed to have perished after it caught fire and sank. Autopsies on the two recovered bodies are being carried out to determine if the men committed suicide to avoid capture, a characteristic of past North Korean intelligence missions.
The prime minister told reporters after the Security Council meeting that his government will consider new procedures to deal with intruders in Japanese waters.
Mr. Koizumi said the crew on the intruder ship was well prepared and armed and attacked Japan. He says the country should keep in mind the risks of encounters with such ships and should take proper action against them.
A shoot-out with the ship erupted after a day-long pursuit. The chase began when the boat ignored Coast Guard orders to stop after it was spotted within Japan's 200-nautical-mile exclusive economic zone.
China's Foreign Ministry says it is concerned about the use of military force in waters near China and that it will ask Japan for more information about the incident.