evidence: Indonesia’s navy has increased patrols around its Natuna islands in the South China Sea after Chinese and US vessels were detected nearby in international waters, despite saying there the vessels had not caused any disturbance, a navy official said. [...] In 2017, Indonesia renamed the northern reaches of its exclusive economic zone in the South China Sea as the North Natuna Sea, as part of a push back against China’s maritime territorial ambitions. [...] China has not claimed the Natuna islands but says it has nearby fishing rights within a self-proclaimed "nine-dash line" that includes most of the energy-rich South China Sea.