President Roh Tae-woo on Saturday promised amnesty for political prisoners as tens of thousands of students and workers battled riot police to demand sweeping reforms.

Roh's promise was seen as an attempt to defuse the political crisis facing his government, which was reeling from a series of scandals even before the fatal police beating of a student April 30 prompted the nationwide protests.Thousands of militant students and workers hurling rocks and flaming firebombs battled riot police Saturday in Seoul, yelling "Overthrow Roh Tae-woo!" and "Murderous regime!"

News reports said at least 40,000 protesters staged rallies in the capital and the cities of Taegu, Pusan, Kwangju, Masan, Ulsan and Songnam. There were no reports of injuries or arrests.