Thousands of radical students yelling anti-government and anti-American slogans battled police with rocks and firebombs in six cities Tuesday to mark a 1980 uprising.

Waves of students hurling firebombs, rocks and bricks fought riot police around college campuses in Seoul and the provincial cities of Kwangju, Taejon, Chongju, Pusan and Chonju.Yonhap, the Korean news agency, reported that 22,000 students at 58 colleges took part in confrontations and peaceful protests but did not give a breakdown. News reports estimated 9,000 students participated in the unrest that started Monday in Seoul and other cities.