Taiwan’s coast guard detained a cargo ship and its Chinese crew on Tuesday and said it was investigating whether the vessel had deliberately cut an undersea telecoms cable in the latest possible breach of the island’s communication lines.

China's government said on Wednesday that Taiwan was "manipulating" possible Chinese involvement in the latest severing of an undersea communications cable, saying the island was casting aspersions before the facts were clear.

TAIPEI—Taiwan detained a cargo ship and its eight Chinese crew members after an undersea fiber-optic cable was severed, in a stepped-up effort to police such incidents, which are often seen as part of China’s pressure campaign targeting the self-ruled island.