China has hit out at planned U.S.-South Korean joint naval exercises in the Yellow Sea at the weekend, saying it opposes any military operations near its territorial waters.
"We oppose any party to take any military actions in our exclusive economic zone without permission," foreign ministry spokesman Hong Lei said in a statement carried by the official Xinhua news agency on Friday.
A U.S. aircraft carrier battle group was heading for the Yellow Sea for the four-day drill starting Sunday, a show of force designed to deter North Korea, which shelled the Yeonpyeong island in the South on Tuesday.
"As the Korean Peninsula situation is highly complicated and sensitive, all parties concerned should stay calm and exercise restraint," Hong was quoted as saying.
He called for the countries concerned to promote peace and stability in the Korean peninsula.
In a flurry of diplomatic activity, Beijing held phone talks on Friday with U.S. Secretary of State Hillary Clinton on the tense situation in the Korean peninsula.
China's foreign minister Yang Jiechi spoke to his South Korean counterpart and met Pyongyang's ambassador to Beijing to discuss the situation.
Chinese official comments have been low-key in the wake of Tuesday's attack, which left four dead, and Beijing has conspicuously refrained from condemning Pyongyang along with the rest of the international community.
Chinese analysts said Beijing's muted reaction stemmed from the fact that China finds itself in a very awkward position as North Korea's ally.
"It must have been fairly clear to the Chinese that if they didn't come out and say something about [the attacks], that the U.S. wouldn't save their face," said Lin Changsheng of the California-based Claremont Institute.
"If a war did start ... things would get very awkward for China," he said.
New Jersey-based China scholar Cheng Xiaonong said the relationship between China and North Korea draws its parallels from the special relationship between former supreme Chinese leader Mao Zedong and the Soviet Union during the 1950-53 Korean War.
"Mao Zedong ... used this as protection during a number of clashes and provocations in East and Southeast Asia, and to shore up his own political position," Cheng said. "North Korea is following the same path today as Mao did then."
"In such a situation, China is in fact North Korea's ally, but it keeps nonetheless being pulled into various sorts of trouble by North Korea," he said.
Cheng said North Korea is also hampering Beijing's efforts to build good relations with its increasingly mistrustful Asian neighbors.
"China in fact has no good strategy to restrain North Korea, and it doesn't need them for anything," he said.
"So it keeps a low profile and keeps silent on the subject of the six-party talks."
Multilateral talks aimed at ending North Korea's nuclear weapons program have been suspended since late 2008.
North Korea staged an artillery firing drill on Friday near the South Korean border, with official media warning that the joint U.S.-South Korean naval exercises would bring the peninsula closer to war.
Lin said North Korea's recent provocations were a strategic move that has left the South Korean government vulnerable.
"Ever since the Cheonan incident, right through to the recent artillery shelling, we have seen North Korea make preparation for war," said Lin, referring to the sinking of a South Korean naval vessel in March.
"The Cheonan incident is still murky, and now the South Korean military has taken another beating with the shelling," he said.
Cheng agreed, saying that the lack of preparedness of the South Korean military had left it open to manipulation by Pyongyang.
"This latest provocation is one of a range of strategies employed by North Korea," he said.
"The lack of military preparation in South Korea ... can be traced back to the policy failures of the two previous presidents, and North Korea is exploiting this to the utmost," Cheng said.
Reported He Ping for Radio Free Asia's Mandarin service. Translated and written in English by Luisetta Mudie.