South Korean police arrested nearly 160 people at an overnight rally in downtown Seoul opposing the resumption of US beef imports.
About 5,500 people rallied in the capital yesterday, a national holiday in South Korea, and the protest continued until early Saturday, when police fired water cannons to disperse the crowd.
Some minor scuffles occurred between police and demonstrators, a police official said on condition of anonymity, citing an office policy.
Police arrested 157 people on charges of staging unauthorized demonstrations, illegally occupying streets and defying orders to disperse, the official said.
The first shipment of US beef under a controversial import deal arrived in South Korea last month, amid lingering public concerns over mad cow disease.
South Korea struck the import deal with Washington in April, and it was followed by weeks of protests around the country.
South Korea was the third-largest overseas market for US beef until it banned imports after a case of mad cow disease was detected in 2003, the first of three confirmed cases in the United States.
Protests against US beef imports have gradually subsided, but civic groups tried to launch a large-scale rally on Friday, saying it would mark their 100th major demonstration against the imports.