The exercises were held in "recent days", China's Defense Ministry said in a brief statement on Sunday, without giving an exact geographical location.
"These drills were routine arrangements in accordance with annual plans for the military," it said, without elaborating, Presstv Reported.
The drills, however, come in the wake of a further escalation in Sino-US ties over the planned arms sales to Taiwan and a visit by the self-ruled island's unruly President Tsai Ming-yen to the United States.
China regards Taiwan as a wayward province, to be taken by force if needed.The rising superpower is becoming increasingly assertive with the United States over its inroads into the South China Sea which Beijing views a crucial backyard.
China's southeast coast, where the drills were held, is one of the country's most sensitive regions as it faces Taiwan across the narrow Taiwan Strait.
The United States officially recognizes the “one-China” principle, under which Taiwan should rejoin China, but Washington is courting Taipei in an attempt to counter Beijing.
On Monday, the Pentagon said the US State Department had approved a deal to sell $2.2-billion worth of tanks, missiles and related equipment to Taiwan.
The announcement angered China which said on Friday it would impose sanctions on US firms involved in the deal. Chinese Foreign Minister Wang Yi warned the United States “not to play with fire”.
It came as Tsai was in New York en route to visit four Caribbean allies. In a statement on Sunday, Taiwan’s Presidential Office said Tsai had spoken with US House Speaker Nancy Pelosi and met with other senators and members of Congress.
Tsai said Taiwan and the US can both forge even closer ties, and also thanked the United States for “the importance it attaches to the security of the Taiwan Strait” and the recently announced arms sale, the statement said.
Tsai was last in the United States in March, but her transit stops this time will be unusually long, in which she will spend four nights on US soil, underlining the Trump administration's extensive support for her.
The developments are likely to prompt China to step up its assertive ways. China has in recent years expanded its military drills in response to the United States' Asia pivot policy.
It has regularly been flying what Beijing calls "island encirclement" exercises and sending warships into the waters around Taiwan.