Air-raid bunkers on the South Korean island of Yeonpyeong shook during the RoK's live-fire artillery exercise, which went on for more than 90 minutes.

But the DPRK guns that had shelled the island after a similar drill last month stayed silent, bringing a measure of relief in a crisis that raised fears of war along one of the world's most heavily fortified frontiers.

"The revolutionary armed forces of the DPRK did not feel any need to retaliate against every despicable military provocation," the official KCNA news agency said, quoting a communique from the Korean People's Army Supreme Command that called the drills a "childish play with fire."

The U.N. Security Council remained deadlocked in its efforts to ease tensions on the Korean peninsula, but the DPRK's refraining from retaliation and the nuclear offer reportedly made to U.S. trouble-shooter Bill Richardson offered some breathing space.

Reuters