Radical students Wednesday demanded a new round of anti-government protests after a demonstrator set himself afire and plunged to his death from a university building.

Cabinet ministers, meanwhile, held emergency meetings to seek ways to deal with the growing crisis, the most serious since President Roh Tae-woo took office in 1988, news reports said.Opposition leader Kim Dae-jung appealed for non-violent protests, warning that any attempt to overthrow the government could lead to military intervention.

Protests have shaken South Korea since police fatally beat a student April 26. Four people have set themselves afire to protest the beating. Two students have died and another was in critical condition.

Earlier Wednesday, a protester identified as Kim Ki-sul, 27, doused himself with paint thinner, set himself on fire and jumped off the roof of the five-story main building at Seoul's Sogang University.

An alliance of 40 student, dissident and political groups said nationwide demonstrations would be held Thursday in Seoul and 40 cities. Police warned protests would be blocked by force and punished.

Kim Dae-jung's appeal for calm came as a radical students continued a sit-in at his office that began Tuesday in an effort to persuade the opposition to join forces in toppling the government.

"The day of military coups is over," Kim told a news conference.

He warned people may see another "military intervention if we try to overthrow the government by force." Kim urged Roh to devote himself to political reform.

Dissidents, radicals and opposition politicians have demanded the resignation of the Cabinet and broader economic and political reforms.

Lee Ki-taek, head of the nation's second opposition group, demanded Roh change his Cabinet immediately or step down.