The exercises were overseen by General Chen Bingde, Chief of General Staff for the three-million-strong People's Liberation Army, the Defense Ministry said on its website (www.mod.gov.cn).
The ministry's statement did not say exactly where the drills took place or how many ships or sailors participated. It said guided missiles were fired and anti-aircraft attacks simulated, as well as electromagnetic interference.
"Pay close attention to changes in the development of the mission, soundly prepare for combat," the ministry paraphrased Chen as saying.
China was furious after it was ambushed at Asia's top security forum last week by a discussion of sensitive territorial claims in the South China Sea, an area rich in energy and key for shipping. China has long-standing territorial disputes there with Brunei, Malaysia, Taiwan, the Philippines and Vietnam.
Beijing had kept serious discussion of the South China Sea off the agenda of the ASEAN Regional Forum (ARF) for a decade and a half. But last week in a meeting in Hanoi, 12 of the 27 members -- including some with no direct stake in the territorial disputes -- raised maritime issues.
China's Foreign Ministry accused U.S. Secretary of State Hillary Clinton of a barely disguised assault on Chinese interests by bringing up the topic.
Chinese state media has since weighed in, warning the United States to alter its policy to take account of China's role as a major player on the world stage if it wants to avoid friction and instability.