The ruling Grand National Party, however, managed to collect two seasts out of five in the Gangneung in Gangwon Province and Yangsan in South Gyeongsang Province, that are traditionally thought to be strongholds of the conservative ruling party.

Results of the polls, however, will not affect the general makeup of the 289-seat National Assembly where Lee's ruling Grand National Party has a majority with 167 seats compared to the main opposition Democratic Party's 83.

The main opposition candidates, who won the polls are Kim Young-hwan, 54, and Lee Chan-ryul, 50,in Ansan's Sangrok B and Suwon-Jangan in Gyeonggi Province. DP’s Chung Beom-gu, 55, also defeated his GNP contender in Jeungpyeong-Jincheon-Goesan-Eumseong of North Chungcheong Province.

The ruling GNP candidate Kwon Seon-dong, 49, got the victory in Gangneung along with another GNP contender Park Hee-tae, former party chairman, in Yangsan , widely seen as political strongholds of former President Roh Moo-hyon who killed self in earlier this year.

The voter turnout for the by-elections was tallied at 39 percent, slightly lower than the 40.8 percent recorded in the April 29 by-elections. Out of 864,860 eligible voters, 337,085 went to the polls to cast their ballots.

Of the 17 rounds of by-elections held since June 2000, only eight recorded a voting rate exceeding 30 percent

The elections are also expected to affect the government's attempt to scale back a project _ initiated by the previous administration _ to relocate nine of 15 government ministries away from Seoul to a provincial region of Sejong City in central South Korea.

The Lee administration believes it is inefficient to scatter government offices.