The United States and South Korea have begun four days of joint military exercises in the waters off the Korean coast, in an effort to deter North Korea from launching further attacks across its border with the South.
An American nuclear-powered aircraft carrier, the USS George Washington, is leading the drill, which comes just days after North Korean forces shelled the South Korean island of Yeonpyeong, killing two marines and two civilians.
North Korea's state-run media has criticized the drills, warning the two Koreas are on "the brink of war."
Earlier Saturday, China launched a flurry of diplomatic activity to ease tensions on the Korean peninsula after North Korea's shelling of the island.
China has warned it opposes any "unilateral military act" in the area without its permission, referring to the U.S.-South Korean drills.
Admiral Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, told CNN (in an interview due to air Sunday) that, as North Korea's closest ally, China has as much at stake as anyone if the region is destabilized.
North Korea leveled new accusations at South Korea Saturday, charging Seoul was using the civilians on the island of Yeonpyeong as a human shields.
The North's official Korean Central News Agency also said if there were civilian deaths, they were "very regrettable."
During a funeral Saturday for the two marines killed in Tuesday's attack, South Korean Marine commander Lieutenant General Yoo Nak-joon vowed a "thousand-fold" retaliation against the North. The comments to hundreds of high-ranking politicians, generals, religious leaders and civilians were also broadcast nation-wide.
Some information for this report provided by Reuters and AFP.