South Korea and the United States ended Thursday their annual joint military drills aimed at ensuring stability on the divided Korean peninsula.

The 11-day war games, dubbed the "Ulchi Freedom Guardian (UFG)", were the latest in a series of show of force aimed at preventing the Democratic People's Republic of Korea (DPRK) from further provocation, following its alleged involvement in the sinking of a South Korean warship in March which left 46 sailors dead.

The largely computerized UFG war games, which involved some 55, 000 South Korean and 30,000 American troops, came shortly after a large-scale South Korea-U.S. air and naval maneuvers in the Sea of Japan last month in response to the sinking.

Pyongyang, denying its responsibility for the alleged torpedo attack on the warship, condemned the war games for raising tension on the peninsula. It had also promised a "merciless counterblow" against the exercises, but the Seoul authorities said they had not detected any unusual military move in the DPRK.

The UFG has been an annual event since 1975. Some 28,500 U.S. troops have been stationed in South Korea since the 1950-53 Korean War ended with an armistice that left the two Koreas technically at war.