China's military has successfully test-fired a new type of missile into waters near the Korean Peninsula, the defence ministry said.
The announcement comes amid Chinese anger over the deployment in South Korea of a sophisticated US missile defence system.
A brief statement on the ministry's website said the test took place recently in the Bohai Gulf and "achieved the intended result". It did not reveal the type of missile.
Both the timing and the location of the test could be significant, although the test may also have been scheduled well in advance.
The Bohai Gulf lies just west of the Yellow Sea, which separates China from the Korean Peninsula.
The defence ministry said last month that it would respond to the missile defence system's deployment by continuing to test new types of weapons under conditions simulating actual combat.
Beijing opposes the system, known by its acronym THAAD, because its radars are allegedly capable of peering deep into China, allowing the US and its allies to better detect rocket launches and aircraft movements.
Washington says the system is necessary to guard against North Korean missile threats and calls China's concerns unfounded.
A foreign ministry spokesman said that China had no intention of softening its opposition.
"China's position on the issue of THAAD is clear and consistent. We hope South Korea can pay high attention to China's concerns and handle the relevant issue in a proper way," Geng Shuang said.
The Chinese weapon tested was likely a DF-26 intermediate range missile being developed to sink warships, including US aircraft carriers, said Song Zhongping, an expert on military affairs and commentator for Hong Kong's Phoenix TV.
The Bohai Gulf is the preferred location for such tests because it is Chinese territorial waters, Mr Song said.
However, while the DF-26 could be useful against THAAD, China also has several other missiles that are up to the task, he said.
"It hasn't much to do with THAAD directly, but it is a kind of warning" to South Korea and the US, he said.