North Korea protester threatens police trying to extinguish burning icons of North Korea during a demonstration in Seoul, Friday. (AP) YEONPYEONG ISLAND: North Korea Friday upped the ante against the planned US-South Korea joint military drills starting Sunday by launching its own artillery drills within sight of an island it showered with a deadly barrage this week. It also warned that the military maneuvers have put the peninsula on the brink of war. The fresh artillery blasts were especially defiant because they came as the US commander in South Korea, Gen. Walter Sharp, toured the South Korean island to survey damage from Tuesday's hail of North Korean artillery fire that killed four people. None of the latest rounds hit the South's territory, and US military officials said Sharp did not even hear the concussions, though residents on other parts of the island panicked and ran back to the air raid shelters where they huddled earlier in the week as white smoke rose from North Korean territory. Separately, China also issued a warning against military acts near its coastline ahead of US-South Korean naval exercises. Beijing's warning came as the Seoul government named a career soldier as its new defense minister amid mounting criticism of the response to Tuesday's attack by North Korea, its heaviest bombardment since the 1950-53 Korean War. “The situation on the Korean peninsula is inching closer to the brink of war due to the reckless plan of those trigger-happy elements to stage again war exercises targeted against the (North),” the North's official KCNA news agency said. The aggressive language is typical of North Korean state-owned media, but the heightened tension was enough to depress the won as much as 2.2 percent. The stock market closed 1.3 percent down, in line with the wider region. Tensions have soared between the Koreas since the North's strike Tuesday destroyed large parts of this island, killing two civilians as well as two marines in a major escalation of their sporadic skirmishes along the sea border. The attack – eight months after a torpedo sank a South Korean warship further west, killing 46 sailors – has also laid bare weaknesses in South Korea's defense 60 years after the Korean War. The skirmish forced South Korea's beleaguered defense minister to resign Thursday, and President Lee Myung-bak Friday named former Joint Chiefs of Staff chairman Kim Kwan-jin to the post. The heightened animosity between the Koreas is taking place as the North undergoes a delicate transition of power from leader Kim Jong-il to his young, inexperienced son Kim Jong-un, who is in his late 20s and is expected to eventually succeed his ailing father.