TAIPEI - About 40 fishermen from four Taiwanese boats were held in Myanmar after being intercepted by naval forces, apparently on suspicions of illegal fishing, an official and media said here Monday.

"We can confirm four fishing boats registered in (south Taiwan's) Pingtung county have been held in Yangon since last week," said Tsay Tzu-yaw, deputy director of Taiwan's Fishery Administration.

Just a handful of the fishermen were Taiwanese, including the captains, while the crew consisted of mostly Filipinos and Indonesians, the Taipei-based China Times reported.

According to the China Times, the four boats left the Thai island of Phuket on November 18.

They reported being chased by the Myanmar military the following day, before radio contact was lost.

Tsay told AFP it remained unclear why the boats were seized, but the China Times reported Monday the four vessels entered Myanmar's exclusive economic zone without permission.

Under the law of the sea, a nation has the right to outline an exclusive economic zone stretching up to 200 nautical miles from its shores and claim the right to exploit the resources within that area.

"The administration has asked (Taiwan's) ministry of foreign affairs for assistance to get information about the incident," Tsay said.

Tsay said once the government had established the reason why the fishermen had been detained, it would make efforts to get them home.