Taiwanese authorities this week said they were investigating a Chinese-owned cargo ship suspected of dragging its anchor over an international subsea telecoms cable northeast of the island.

"DPP authorities have... out of thin air deliberately hyped the subsea cable incident as a so-called 'grey-zone threat' from the mainland, fully showing they will not let go of unscrupulous 'anti-China counter-China' tricks," state broadcaster CCTV quoted Taiwan Affairs Office spokesman Chen Binhua as saying, referring to the island's ruling Democratic Progressive Party.

Taiwan's top China policy body, the Mainland Affairs Council, hit back Wednesday, saying the prosecutors' investigation was "based on relevant evidence" and there was no "anti-China" issue.

The Cameroon-flagged Shunxing39 was intercepted by Taiwan's coast guard on Friday after Chunghwa Telecom reported damage to a subsea cable that is part of the Trans-Pacific Express Cable System.

Coast guard personnel were unable to board the ship due to rough seas and it was allowed to sail for South Korea.

"An analysis of the ship's historical trajectory has yet to reveal its true intent", Taiwan's coast guard said on Tuesday.

"However, the possibility of a Chinese-flag of convenience ship engaging in grey-zone harassment cannot be ruled out", it added, referring to tactics that fall short of an act of war.

Taiwan Affairs Office spokesman Chen dismissed the allegations, saying damage to subsea cables was "a common maritime occurrence" with "more than a hundred incidents" in the world each year.

But the Mainland Affairs Council said: "China's flag of convenience vessels have a notorious reputation in the international community".

A Chinese-flagged bulk carrier is suspected of involvement in the cutting of two telecommunications cables in Swedish territorial waters in November.

A senior Taiwan coast guard official said the captain of the Shunxing39 told them the ship had been "dragging anchor", but Taiwanese authorities had no "clear evidence" to prove the vessel had damaged the cable.

China regards Taiwan as part of its territory and has threatened to use force to bring the self-ruled island under its control.

In recent years, Beijing has ramped up military pressure on Taipei, which fears China could attempt to sever communication links to the island.

In February 2023, two undersea telecoms lines serving Taiwan's outlying Matsu archipelago were cut, disrupting communications for weeks.

Taipei's Communications Commission and locals said at the time that Chinese fishing vessels or sand dredgers may have done the damage.

The world's data and communications are carried across oceans by great bundles of subsea fibre optic cables -- with their high strategic value making them potential targets for attack.

mya-joy/amj/sco

CHUNGHWA TELECOM