TAIPEI (Taiwan News) — The Coast Guard said a submarine communications cable between Taiwan and Penghu was cut on Tuesday morning, and a Togo-flagged ship with a Chinese owner and crew is suspected to be responsible.

The Coast Guard said the case is being investigated as a national security issue. In a press release released midday Tuesday, the Coast Guard said it is unclear if the incident was intentional, though it has not ruled out the possibility it was a “Chinese gray zone intrusion operation.”

Chunghwa Telecom notified the Coast Guard the cable had been cut at around 2:30 a.m. Tuesday and asked it to investigate, the release said. Communications on the outlying Penghu Islands were not affected as a backup cable was activated.

After receiving the report, the Coast Guard dispatched a vessel and found the Togolese cargo ship named Hongtai 168 (宏泰) anchored near the site and unable to move. The Coast Guard said boarding was unsuccessful due to poor weather conditions and backup was sent to escort the ship to Anping Port in Tainan.

The Coast Guard said the ship arrived at the port around midday Tuesday. It said the ship's eight crew and owner were Chinese nationals, and it is working with Tainan prosecutors to clarify the facts of the case.

Coast Guard members board the ship on Tuesday. (Coast Guard Administration video)