Shouting "Oppose Bush's visit," several hundred radical students attacked a U.S. cultural center with firebombs and steel pipes Thursday and at least six policemen were hurt, officials said.

It was the third time the U.S. center in downtown Kwangju had been attacked by radicals in less than a month.Witnesses said 200 to 300 students stormed the center's compound and briefly occupied its courtyard, smashing windows and tossing firebombs, before being driven away by police firing tear gas.