China has stepped up its claim to the South China Sea by building a new underwater surveillance system as tensions with the US rise. Beijing has built a system known as the “Blue Ocean Information Network”, according to research from the Asia Maritime Transparency Initiative.

This could allow Beijing to persistently monitor contested waters or a disputed island giving them a military advantage. The research paper said the new systems are intended “to host a number of different sensors and act as a communications conduit for the information that they collect.”

Dr Collin Koh, a Research Fellow at RSIS said that the zone fully encompasses sensitive areas and was not just political symbolism.