The number of Chinese maritime militia vessels around key features across the South China Sea grew by 35% last year as Beijing continued to bolster its presence amid rising regional tensions, according to data by the Washington-based Asia Maritime Transparency Initiative (AMTI).

A report released on Wednesday and based on satellite imagery of nine features in the sea, including reefs and shoals, identified an average of 195 militia ships present on any given day.

The increase from a year earlier was accompanied by "a dramatic shift” in vessels to Mischief Reef in the summer of 2023 when over 180 boats were observed gathered there from July. The reef is also claimed by the Philippines and Vietnam.