Police fire water cannon on thousands of South Koreans protesting against US beef imports

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A crowd estimated by police at 38,000 people filled a plaza in front of city hall. Protesters lit candles, waved placards and chanted slogans criticizing President Lee Myung-bak.
The rally was largely peaceful, with most protesters dispersing voluntarily. But sporadic clashes between some protesters and police continued into the early hours of Sunday.
South Korea agreed in April to reopen what was formerly the third-largest overseas market for U.S. beef. It had been shut most of the past 4 1/2 years following the first U.S. case of mad cow disease in a Canadian-born cow in Washington state in 2003.
That deal, coupled with some sensational media reports, sparked fears of mad cow disease and triggered protests calling for scrapping or renegotiating the agreement.
Students, labor union members, office workers were among those who filled the plaza, which was surrounded by special buses used by riot police.
Anger has intensified since Thursday, when the government announced it would implement the April 18 agreement with Washington and resume beef imports within days despite widespread public opposition.
Rallies in recent days have ended with protesters marching through downtown streets, where some scuffles with police have resulted. Police said they deployed about 11,000 personnel to protest sites in the capital Saturday to guard against possible violence.
The beef issue has emerged as the biggest domestic challenge for Lee's fledgling administration. The former construction industry chief executive took office Feb. 25 on a vow to boost the economy and is approaching his 100th day in office.
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