China's decision to give its top military body control over the country's vast coast guard has increased concerns about the risk of miscalculation in the disputed waters of East Asia.

The ruling Communist Party is transferring authority over Asia's biggest coast guard fleet to the Central Military Commission from the civilian State Oceanic Administration, as part of a sweeping government overhaul announced last week in Beijing.

It will give President Xi Jinping — China's commander in chief — direct control over the ships that the country often relies on to assert territorial claims across the region.