South Korea's ruling party has won parliamentary by-elections, giving a boost to President Lee Myung-bak halfway through his five-year term.
The National Election Commission said Thursday that Lee's Grand National Party won five of the eight vacant parliamentary seats at stake during Wednesday's vote.
The elections were considered a gauge of public support for Lee's conservative government, which is grappling with tension over the sinking of a South Korean warship blamed on North Korea.
The GNP now has 172 seats in the 299-member unicameral National Assembly.
The GNP suffered a surprise defeat in last month's mayoral and gubernatorial elections, dealing a blow to Lee, who favors a tough policy on North Korea.