James Chang, deputy spokesman for the foreign ministry, said the four ships were intercepted by Myanmar's navy Nov. 18, probably because they had intruded into that country's exclusive economic zone.

In addition to two ships from Pingtung County -- the Ho Yi Fa from Linbian and the Ming Cheng Yi from Donggang -- whose seizure the deputy spokesman confirmed earlier Monday, Chang listed the Hung Fa 128 and the Chin Ming Tsai 130, both from Donggang, as the two other vessels taken over by Myanmar authorities.

Chang did not disclose how many crew members were on board the two ships, saying only that the Hung Fa 128 has a Taiwanese captain.

The nationality of the other ship's captain remains unclear.

Local fishing officials said, however, that the four ships have a total of 40 crew members.

Chang said earlier Monday that the Ho Yi Fa has a Taiwanese skipper and 11 Filipino crew members, while the Ming Cheng Yi has nine Indonesian crew in addition to its Taiwanese skipper.

Chang said the foreign ministry is doing its utmost to help the ships' owners secure the release of their vessels as soon as possible.

The ships were four of 17 foreign fishing boats seized by Myanmar's Navy, according to wire service reports. Some 120 crew members of these boats were said to be detained in Insein Prison near Yangon, Myanmar's biggest city and its former capital.

(By Shih Sinyao and Maubo Chang)