Taiwan Detains Chinese-Linked Ship Suspected of Severing Undersea Cable

In this file image, a member of the Taiwan Coast Guard monitors a China Coast Guard boat as it passes near the coast of Matsu islands, Taiwan, on Oct. 14, 2024, in a still from video. Taiwan Coast Guard via AP

Taiwan’s coast guard said on Tuesday it had detained a cargo ship linked to China after an undersea cable to the Penghu Islands was severed.

The coast guard issued a statement saying the Hong Tai 58, a ship crewed by Chinese nationals but flying a flag of convenience—the African country of Togo—was intercepted in waters between Taiwan’s west coast and the Penghu Islands.

The coast guard said they were notified by telecommunications provider Chunghwa Telecom that one of its undersea cables had been severed 6 nautical miles northwest of the fishing harbor of Jiangjun.

The Taiwanese government has complained about so-called gray zone activities by the Chinese in recent years, including balloon overflights, sand dredging, and tampering with undersea cables.

Last month Taiwan said it would step up surveillance of ships flying under flags of convenience after a Chinese vessel, registered in Cameroon and Tanzania, was accused of severing an undersea cable off the port of Keelung on Jan. 3.

That incident prompted the Taiwanese navy and other agencies to step up efforts to protect undersea cables which keep the island nation connected to the rest of the world, the coast guard said in a statement, adding that further investigation is needed.

China claims Taiwan as its own territory, and although the Chinese Communist Party (CCP) has never governed the island, Chinese leader Xi Jinping has repeatedly pledged to achieve “reunification” and has reserved the right to use force.

In the latest incident, the coast guard said the Hong Tai 58 had been anchored close to where the cable was severed, and it had not responded to seven signals which had been transmitted by the authorities in the port of Anping between Feb. 22 and the early hours of Feb. 24.

It then began to sail northwestward, but was intercepted by three coast guard vessels and escorted to Anping.

The Taiwanese authorities said the case was being handled sensitively, “in accordance with national security-level principles.”

Possible ‘Gray Zone Harassment’

In a statement, the coast guard said, “All eight crew members are Chinese nationals and [we] do not rule out the possibility of the Chinese activity of gray zone harassment.”

“The cause of the underwater cable break, whether it was due to intentional sabotage or simply an accident, is still pending further investigation for clarification,” the statement added.

Taiwan’s digital ministry said communications between Taiwan and the Penghu Islands were not affected by the incident, as services were redirected to other cables.

In February 2023 communications with the Taiwan-administered Matsu Islands—off the coast of China’s Fujian province—were disrupted for weeks after two undersea cables were severed.

The islands’ 14,000 residents were cut off from the internet and unable to use text messaging.

Taiwanese authorities said at the time that, based on AIS (automatic identification systems) ship tracking data, three Chinese vessels appeared to be responsible for the damage.

Taiwan’s digital ministry said there had been five cases of undersea cable malfunctions this year, compared with three each in 2024 and 2023.

Investigations have revealed patent applications that suggest researchers in China have been developing technologies to sabotage undersea cables.

One such patent application, revealed in a Jan. 2025 Newsweek investigation, showed researchers at China’s Lishui University sought in 2020 to develop an anchor-shaped “ocean towing type cutting device.”

Why Use Flag Of Convenience?

There are many reasons why a ship might fly a flag of convenience, which means registering with a country which is not that of the ship’s actual owner, or home port.

It can be a commercial decision as some countries charge much lower registration fees and do not impose such high levels of maritime bureaucracy as nations such as the United States, Britain, and France.

But sometimes, as in the case of Russia’s so-called shadow fleet, the reason is more sinister and implies a deliberate deception, to obscure the true nature of the vessel.

There have been several incidents in the Baltic Sea of undersea cables having been tampered with, including one instance which involved a Chinese ship.

In Nov. 2024 the Yi Peng 3, a Chinese-owned and operated cargo ship, is alleged to have cut a communication cable connecting Finland and Germany, and another connecting Lithuania and Sweden.

A Chinese Foreign Ministry spokesperson said during a regular press briefing on Tuesday he was not aware of the issue involving the Hong Tai 58, and would not comment on it.

The Associated Press and Reuters contributed to this report.