SEOUL, South Korea -- A high-seas confrontation between North and South Korea escalated Tuesday when southern warships sunk one northern vessel and badly damaged at least one other in a clash in the Yellow Sea.
About 30 North Korean sailors are believed dead and others injured, a U.S. defense official said Tuesday in Washington.U.S. Navy and Air Force planes increased patrol flights over the Yellow Sea, and the United States may send additional ships or other resources to the region, according to the defense official, who spoke on condition of anonymity.
While South Korea blamed the northern ships for the 10-minute exchange of gunfire, the North Korean state news agency accused the south of a "deliberate" provocation that drives the two Koreas "to the brink of war." It demanded an apology.
Ships from the two sides have been confronting each other since June 8, when North Korean warships began sailing in and out of a disputed crab fishing area. Tuesday's shooting came less than an hour before the U.S.-led U.N. Command met with northern generals in a bid to defuse tensions.
The United States and China expressed concern. Mike Hammer, a spokesman for the U.S. National Security Council, said it appeared the situation has eased.
"There has been separation at sea, with North Korean ships moving back north," he said.
Brig. Gen. Cha Young-koo, a South Korean Defense Ministry spokesman, said the exchange began after southern ships twice tried to chase the northern ships out of the contested zone. A northern torpedo boat opened fire when a southern patrol boat tried to ram it, he said.
"All responsibility lies on the North Korean side," Cha said, saying the South Koreans fired in self-defense.
The sunken vessel was believed to be an 80-ton Soviet-designed P-6 torpedo ship. A 400-ton Taechong 2 patrol boat appeared to be sinking after being raked by South Korean fire, said Col. Hwang Dong-kyu, a spokesman for the south's Joint Chiefs of Staff.
A statement from the Defense Ministry later Tuesday said the patrol boat appeared to have managed to retreat to North Korean waters.
Hwang said seven South Korean sailors were injured when their ships, a frigate and a patrol boat, were hit by northern fire. There was no word on North Korean casualties. Five other northern ships retreated from the zone, he said.
North Korea's official Korean Central News Agency said one ship was sunk and three others were badly damaged.
The disputed waters lie midway between the North Korean mainland and five South Korean islands, 60 miles northwest of Seoul. The zone is within the territorial waters -- 12 nautical miles -- of both sides.
Generals from North Korea lodged a protest against the shooting when they sat down 40 minutes later with generals from the U.N. Command in the border village of Panmunjom for their scheduled meeting.
The U.N. Command said its generals urged both sides to withdraw their naval forces from the area, but the negotiators "were unable to reach agreement on the issue of reducing tensions."
The talks recessed while the North Korean officers conferred with their leaders in Pyongyang, the northern capital, the U.N. Command said.
South Korean Defense Ministry officials, speaking on condition of anonymity, said North Korea's delegation came to the talks with detailed information about the fighting, suggesting it had been planned.
The northern officials caught the U.N. delegation off guard by making detailed charges and an American general had to telephone Seoul to find out what was going on, the ministry officials said.
South Korea ordered its military to a heightened state of readiness on the islands within the disputed zone, moving more soldiers and weapons into guard posts. The military has been canceling leaves for soldiers since Saturday.